Modulation of TMPRSS6 expression

ABSTRACT

Disclosed herein are antisense compounds and methods for modulating TMPRSS6 and modulating an iron accumulation disease, disorder and/or condition in an individual in need thereof. Iron accumulation diseases in an individual such as hemochromatosis or β-thalassemia can be ameliorated or prevented with the administration of antisense compounds targeted to TMPRSS6.

SEQUENCE LISTING

The present application is being filed along with a Sequence Listing in electronic format. The Sequence Listing is provided as a file entitled BIOL0162USC2SEQ.txt created Dec. 19, 2017, which is 72 kb in size. The information in the electronic format of the sequence listing is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention provides methods, compounds, and compositions for modulating TMPRSS6 expression for the purpose of reducing iron accumulation in an animal.

BACKGROUND OF THE INVENTION

Maintenance of iron balance in human beings is delicate because of the limited capacity of the human physiology for iron absorption and excretion (Finch, C. A. and Huebers, H. N. Engl. J. Med. 1982. 306: 1520-1528). Iron deficiency is a widespread disorder and results from any condition in which dietary iron intake does not meet the body's demands. Often, pathological blood loss contributes to negative iron balance. Iron overload is also a common condition, and may result from a genetic cause, for example, mutations of different genes of iron metabolism (Camaschella, C. Blood. 2005. 106: 3710-3717). The hepatic peptide hormone, hepcidin plays a key role in body iron metabolism as it controls iron absorption and recycling (Ganz, T. Am. Soc. Hematol. Educ. Program 2006. 507: 29-35; Kemna, E. H. et al., Clin. Chem. 2007. 53: 620-628). Several proteins, including HFE (hemochromatosis protein) (Ahmad, K. A. et al., Blood Cells Mol Dis. 2002. 29: 361), transferrin receptor 2 (Kawabata, H. et al., Blood 2005. 105: 376), and hemojuvelin (Papanikolaou, G. et al., Nat. Genet. 2004. 36: 77) also regulate the body's iron levels.

Transmembrane protease, serine 6 (TMPRSS6) is a type II transmembrane serine protease and is expressed primarily in the liver (Velasco, G. et al., J. Biol. Chem. 2002. 277: 37637-37646). Mutations in TMPRSS6 have been implicated in iron deficiency anemia (Finberg, K. E. et al., Nat. Genet. 2008. 40: 569-571), where the level of hepcidin was found to be unusually elevated. A study of a human population with microcytic anemia found that loss-of-function mutations in the TMPRSS6 gene lead to overproduction of hepcidin, which, in turn, lead to defective iron absorption and utilization (Melis, M. A. et al., Hematologica 2008. 93: 1473-1479). TMPRSS6 participates in a transmembrane signaling pathway triggered by iron deficiency and suppresses diverse pathways of Hamp activation, the gene that encodes hepcidin (Du, X. et al., Science 2008. 320: 1088-1092). Heterozygous loss of TMPRSS6 in HFE^(−/−) mice reduces systemic iron overload, while homozygous loss of TMPRSS6 in HFE^(−/−) mice causes systemic iron deficiency and elevated hepatic expression of hepcidin (Finberg, K. E. et al., Blood 2011. 117: 4590-4599).

An example of an iron overload disorder is Hemochromatosis. Hemochromatosis (e.g. hemochromatosis type 1 or hereditary hemochromatosis) is a disorder that results in excess intestinal absorption of dietary iron from the gastrointestinal tract (Allen, K. J. et al., N. Engl. J. Med. 2008. 358: 221-230). This results in a pathological increase in total body iron stores. Excess iron accumulates in tissues and organs, particularly the liver, adrenal glands, heart, skin, gonads, joints and pancreas, and disrupt their normal function. Secondary complications, such as cirrhosis (Ramm, G. A. and Ruddell, R. G. Semin. Liver Dis. 2010. 30: 271-287), polyarthropathy (Carroll, G. J. et al., Arthritis Rheum. 2011. 63: 286-294), adrenal insufficiency, heart failure and diabetes (Huang, J. et al., Diabetes 2011. 60: 80-87) are common. Another example of an iron overload disorder is β-thalassemia, where patients can develop iron overload caused by ineffective erythropoiesis or transfusions to treat β-thalassemia.

There is a currently a lack of acceptable options for treating iron overload disorders. It is therefore an object herein to provide compounds and methods for the treatment of such diseases and disorders. This invention relates to the discovery of novel, highly potent inhibitors of TMPRSS6 gene expression.

All documents, or portions of documents, cited in this application, including, but not limited to, patents, patent applications, articles, books, and treatises, are hereby expressly incorporated-by-reference for the portions of the document discussed herein, as well as in their entirety.

SUMMARY OF THE INVENTION

Provided herein are methods for modulating the levels of TMPRSS6 mRNA and/or protein in an animal. Provided herein are methods, compounds, and compositions for lowering TMPRSS6 levels. In certain embodiments, lowering of TMPRSS6 results in an increase in hepcidin expression levels. In certain embodiments, lowering of TMPRSS6 results in a decrease in the percentage of saturation of transferrin. In certain embodiments, lowering of TMPRSS6 results in a reduction of iron accumulation. In certain embodiments, such results are effected by administering a TMPRSS6 inhibitor. In certain embodiments, a therapeutically effective amount of a TMPRSS6 inhibitor is administered to an animal. In further embodiments, administration of the therapeutically effective amount of the TMPRSS6 inhibitor also increases hepcidin expression levels. In further embodiments, administration of the therapeutically effective amount of the TMPRSS6 inhibitor also decreases the percentage of saturation of the transferrin molecule in the animal.

In certain embodiments, methods are provided for treating, preventing, delaying the onset of, ameliorating and/or reducing a symptom, of a disease, disorder and/or condition associated with the excess accumulation of iron in an animal. The methods comprise of administering to the animal a therapeutically effective amount of a TMPRSS6 inhibitor, wherein the disease, disorder and/or condition associated with excess iron accumulation is treated, prevented, the onset delayed, the symptom ameliorated and/or reduced.

In certain embodiments, methods are provided for identifying an animal at risk for a disease, disorder and/or condition or having a disease, disorder and/or condition which is associated with excess accumulation of iron. In further embodiments, methods include administering to the animal a therapeutically effective amount of a TMPRSS6 inhibitor, thus treating the animal.

In certain embodiments, provided herein is the use of a TMPRSS6 inhibitor for the preparation of a medicament.

In certain embodiments, provided herein is the use of a TMPRSS6 inhibitor as a medicament for treating, preventing, delaying the onset of, and/or reducing the symptom of a disease, disorder and/or condition associated with excess accumulation of iron in an animal by administering to the animal a therapeutically effective amount of the TMPRSS6 inhibitor.

In certain embodiments, provided herein is the use of a TMPRSS6 antisense compound as an inhibitor of TMPRSS6.

DETAILED DESCRIPTION OF THE INVENTION

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. Herein, the use of the singular includes the plural unless specifically stated otherwise. As used herein, the use of “or” means “and/or” unless stated otherwise. Furthermore, the use of the term “including” as well as other forms, such as “includes” and “included”, is not limiting. Also, terms such as “element” or “component” encompass both elements and components comprising one unit and elements and components that comprise more than one subunit, unless specifically stated otherwise.

The section headings used herein are for organizational purposes only and are not to be construed as limiting the subject matter described. All documents, or portions of documents, cited in this application, including, but not limited to, patents, patent applications, articles, books, and treatises, are hereby expressly incorporated by reference for the portions of the document discussed herein, as well as in their entirety.

Definitions

Unless specific definitions are provided, the nomenclature utilized in connection with, and the procedures and techniques of, analytical chemistry, synthetic organic chemistry, and medicinal and pharmaceutical chemistry described herein are those well known and commonly used in the art. Standard techniques may be used for chemical synthesis, and chemical analysis. Where permitted, all patents, applications, published applications and other publications, GENBANK Accession Numbers and associated sequence information obtainable through databases such as National Center for Biotechnology Information (NCBI) and other data referred to throughout the disclosure herein are incorporated by reference for the portions of the document discussed herein, as well as in their entirety.

Unless otherwise indicated, the following terms have the following meanings:

“2′-O-methoxyethyl” (also 2′-MOE and 2′-O(CH₂)₂—OCH₃) refers to an O-methoxy-ethyl modification of the 2′ position of a furosyl ring. A 2′-O-methoxyethyl modified sugar is a modified sugar.

“2′-O-methoxyethyl nucleotide” means a nucleotide comprising a 2′-O-methoxyethyl modified sugar moiety.

“5-methylcytosine” means a cytosine modified with a methyl group attached to the 5′ position. A 5-methylcytosine is a modified nucleobase.

“About” means within ±10% of a value. For example, if it is stated, “a marker may be increased by about 50%”, it is implied that the marker may be increased between 45%-55%.

“Active pharmaceutical agent” or “Pharmaceutical agent” means the substance or substances in a pharmaceutical composition that provide a therapeutic benefit when administered to an individual. For example, in certain embodiments, an antisense oligonucleotide targeted to TMPRSS6 is an active pharmaceutical agent.

“Active target region” or “target region” means a region to which one or more active antisense compounds is targeted. “Active antisense compounds” means antisense compounds that reduce target nucleic acid levels or protein levels.

“Administered concomitantly” refers to the co-administration of two agents in any manner in which the pharmacological effects of both are manifest in the patient time. Concomitant administration does not require that both agents be administered in a single pharmaceutical composition, in the same dosage form, or by the same route of administration. The effects of both agents need not manifest themselves at the same time. The effects need only be overlapping for a period of time and need not be coextensive.

“Administering” means providing a pharmaceutical agent to an individual, and includes, but is not limited to administering by a medical professional and self-administering.

“Agent” means an active substance that can provide a therapeutic benefit when administered to an animal. “First Agent” means a therapeutic compound provided herein. For example, a first agent is an antisense oligonucleotide targeting TMPRSS6. “Second agent” means a second therapeutic compound described herein. For example, a second agent can be a second antisense oligonucleotide targeting TMPRSS6 or a non-TMPRSS6 target. Alternatively, a second agent can be a compound other than an antisense oligonucleotide.

“Amelioration” refers to a lessening of at least one indicator, marker, sign, or symptom of an associated disease, disorder and/or condition. In certain embodiments, amelioration includes a delay or slowing in the progression of one or more indicators of a condition, disorder and/or disease. The severity of indicators may be determined by subjective or objective measures, which are known to those skilled in the art.

“Anemia” is a disease characterized by a lower than normal number of red blood cells (erythrocytes) in the blood, usually measured by a decrease in the amount of hemoglobin. The cause of anemia can include chronic inflammation, chronic kidney disease, kidney dialysis treatment, genetic disorders, chronic infection, acute infection, cancer and cancer treatments. Altered iron homeostasis and/or erythropoiesis in these diseases, disorders and/or conditions can also result in decreased erythrocyte production. Clinical signs of anemia include low serum iron (hypoferremia), low hemoglobin levels, low hematocrit levels, decreased red blood cells, decreased reticulocytes, increased soluble transferrin receptor and iron restricted erythropoiesis. Examples of anemia include thalassemias (i.e. α-thalassemia, β-thalassemia (minor, intermedia and major) and δ-thalassemia), sickle cell anemia, aplastic anemia, Fanconi anemia, Diamond Blackfan anemia, Shwachman Diamond syndrome, red cell membrane disorders, glucose-6-phosphate dehydrogenase deficiency, hereditary hemorrhagic telangiectasia, hemolytic anemia, anemia of chronic disease and the like.

“Animal” refers to a human or non-human animal, including, but not limited to, mice, rats, rabbits, dogs, cats, pigs, and non-human primates, including, but not limited to, monkeys and chimpanzees.

“Antibody” refers to a molecule characterized by reacting specifically with an antigen in some way, where the antibody and the antigen are each defined in terms of the other. Antibody may refer to a complete antibody molecule or any fragment or region thereof, such as the heavy chain, the light chain, Fab region, and Fc region.

“Antisense activity” means any detectable or measurable activity attributable to the hybridization of an antisense compound to its target nucleic acid. In certain embodiments, antisense activity is a decrease in the amount or expression of a target nucleic acid or protein encoded by such target nucleic acid.

“Antisense compound” means an oligomeric compound that is capable of undergoing hybridization to a target nucleic acid through hydrogen bonding.

“Antisense inhibition” means reduction of target nucleic acid levels or target protein levels in the presence of an antisense compound complementary to a target nucleic acid compared to target nucleic acid levels or target protein levels in the absence of the antisense compound.

“Antisense oligonucleotide” means a single-stranded oligonucleotide having a nucleobase sequence that permits hybridization to a corresponding region or segment of a target nucleic acid.

“Bicyclic sugar” means a furosyl ring modified by the bridging of two non-geminal ring atoms. A bicyclic sugar is a modified sugar.

“Bicyclic nucleic acid” or “BNA” refers to a nucleoside or nucleotide wherein the furanose portion of the nucleoside or nucleotide includes a bridge connecting two carbon atoms on the furanose ring, thereby forming a bicyclic ring system.

“Blood transfusion” refers to the process of receiving blood products into one's circulation intravenously. Transfusions are used in a variety of medical disease, disorder and/or conditions to replace lost blood components.

“Cap structure” or “terminal cap moiety” means chemical modifications, which have been incorporated at either terminus of an antisense compound.

“Chemically distinct region” refers to a region of an antisense compound that is in some way chemically different than another region of the same antisense compound. For example, a region having 2′-O-methoxyethyl nucleotides is chemically distinct from a region having nucleotides without 2′-O-methoxyethyl modifications.

“Chimeric antisense compound” means an antisense compound that has at least two chemically distinct regions.

“Co-administration” means administration of two or more pharmaceutical agents to an individual. The two or more pharmaceutical agents may be in a single pharmaceutical composition, or may be in separate pharmaceutical compositions. Each of the two or more pharmaceutical agents may be administered through the same or different routes of administration. Co-administration encompasses concomitant, parallel or sequential administration.

“Complementarity” means the capacity for pairing between nucleobases of a first nucleic acid and a second nucleic acid.

“Contiguous nucleobases” means nucleobases immediately adjacent to each other.

“Deoxyribonucleotide” means a nucleotide having a hydrogen at the 2′ position of the sugar portion of the nucleotide. Deoxyribonucleotides may be modified with any of a variety of substituents.

“Diluent” means an ingredient in a composition that lacks pharmacological activity, but is pharmaceutically necessary or desirable. For example, the diluent in an injected composition may be a liquid, e.g. PBS.

“Dosage unit” means a form in which a pharmaceutical agent is provided, e.g. pill, tablet, or other dosage unit known in the art. In certain embodiments, a dosage unit is a vial containing lyophilized antisense oligonucleotide. In certain embodiments, a dosage unit is a vial containing reconstituted antisense oligonucleotide.

“Dose” means a specified quantity of a pharmaceutical agent provided in a single administration, or in a specified time period. In certain embodiments, a dose may be administered in one, two, or more boluses, tablets, or injections. For example, in certain embodiments where subcutaneous administration is desired, the desired dose requires a volume not easily accommodated by a single injection, therefore, two or more injections may be used to achieve the desired dose. In certain embodiments, the pharmaceutical agent is administered by infusion over an extended period of time or continuously. Doses may be stated as the amount of pharmaceutical agent per hour, day, week, or month.

“Effective amount” or “therapeutically effective amount” means the amount of active pharmaceutical agent sufficient to effectuate a desired physiological outcome in an individual in need of the agent. The effective amount can vary among individuals depending on the health and physical condition of the individual to be treated, the taxonomic group of the individuals to be treated, the formulation of the composition, assessment of the individual's medical condition, and other relevant factors.

“Fully complementary” or “100% complementary” means that each nucleobase of a nucleobase sequence of a first nucleic acid has a complementary nucleobase in a second nucleobase sequence of a second nucleic acid. In certain embodiments, the first nucleic acid is an antisense compound and the second nucleic acid is a target nucleic acid.

“Gapmer” means a chimeric antisense compound in which an internal region having a plurality of nucleosides that support RNase H cleavage is positioned between external regions having one or more nucleosides, wherein the nucleosides comprising the internal region are chemically distinct from the nucleoside or nucleosides comprising the external regions. The internal region may be referred to as a “gap segment” and the external regions may be referred to as “wing segments.”

“Gap-widened” means a chimeric antisense compound having a gap segment of 12 or more contiguous 2′-deoxynucleosides positioned between and immediately adjacent to 5′ and 3′ wing segments having from one to six nucleosides.

“Hemochromatosis” is a disorder of iron metabolism that results in excess iron being absorbed from the gastrointestinal tract, leading to excess iron accumulation and deposition in various tissues of the body. Primary or hereditary or classic hemochromatosis is caused by a genetic mutation, for example, in the HFE gene. Subjects with this disease have excess amounts of iron, which is absorbed in the gastrointestinal tract and builds up in the body tissues, particularly in the liver. Secondary or acquired hemochromatosis can be caused by frequent blood transfusions, high oral or parenteral intake of iron supplements, or a secondary effect of other diseases.

“Hematopoiesis” refers to the formation of cellular components of the blood, derived from hematopoietic stem cells. These stem cells reside in the medulla of the bone marrow and have the unique ability to give rise to all the different mature blood cell types.

“Hemolysis” refers to the rupturing of erythrocytes or red blood cells and the release of their contents into surrounding fluid. Hemolysis in an animal may occur due to a large number of medical conditions, including bacterial infection, parasitic infection, autoimmune disorders and genetic disorders.

“Hepcidin” refers to both an mRNA as well as a protein encoded by the mRNA that is produced by hepatocytes in response to inflammation or to rising levels of iron in the blood. The primary role of hepcidin is to regulate blood iron levels by facilitating a decrease in these blood iron levels. Hepcidin expression is increased in conditions of acute and chronic inflammation resulting in decreased iron availability for erythropoiesis. “Hepcidin” is also referred to as hepcidin antimicrobial peptide; HAMP; HAMP1; HEPC; HFE2; LEAP-1; LEAP1; and liver-expressed antimicrobial peptide.

“Hereditary anemia” refers to anemia which is caused by a hereditary condition that causes red blood cells in the body to die faster than normal, be ineffective in transporting oxygen from the lungs to the different parts of the body, or not be created at all. Examples include, but are not limited to, sickle cell anemia, thalassemia, Fanconi anemia, Diamond Blackfan anemia, Shwachman Diamond syndrome, red cell membrane disorders, glucose-6-phosphate dehydrogenase deficiency, or hereditary hemorrhagic telangiectasia.

“HFE” refers to the human hemochromatosis gene or protein.

“HFE gene mutation” refers to mutations in the HFE gene, which may result in hereditary hemochromatosis.

“Hybridization” means the annealing of complementary nucleic acid molecules. In certain embodiments, complementary nucleic acid molecules include an antisense compound and a target nucleic acid.

“Identifying an animal at risk for or having a disease, disorder and/or condition associated with excess accumulation of iron” means identifying an animal having been diagnosed with a disease, disorder and/or condition or identifying an animal predisposed to develop a disease, disorder and/or condition associated with excess accumulation of iron. Individuals can be predisposed to develop a disease, disorder and/or condition associated with excess accumulation of iron in individuals with a familial history of hemochromatosis. Such identification may be accomplished by any method including evaluating an individual's medical history and standard clinical tests or assessments.

“Immediately adjacent” means that there are no intervening elements between the immediately adjacent elements.

“Individual” or “subject” or “animal” means a human or non-human animal selected for treatment or therapy.

“Inhibiting the expression or activity” refers to a reduction or blockade of the expression or activity of a RNA or protein and does not necessarily indicate a total elimination of expression or activity.

“Internucleoside linkage” refers to the chemical bond between nucleosides.

“Intravenous administration” means administration into a vein.

“Iron accumulation” or “iron overload” indicates accumulation and deposition of iron in the body from any cause. The most common causes are hereditary causes, transfusional iron overload, which can result from repeated blood transfusions, or excessive dietary iron intake.

“Iron supplements” refer to supplements prescribed for a medical reason to treat iron deficiency in a patient. Iron can be supplemented by the oral route or given parenterally.

“Linked nucleosides” means adjacent nucleosides which are bonded together.

“Marker” or “biomarker” is any measurable and quantifiable biological parameter that serves as an index for health- or physiology-related assessments. For example, an increase in the percentage saturation of transferrin, an increase in iron levels, or a decrease in hepcidin levels can be considered markers of an iron overload disease, disorder and/or condition.

“MCH” refers to “mean corpuscular hemoglobin” or “mean cell hemoglobin”, a value to express the average mass of hemoglobin (Hb) per red blood cell in a sample of blood.

“MCV” referes to “mean corpuscular volume” or “mean cell volume”, a value to express the average red blood cell size.

“Mismatch” or “non-complementary nucleobase” or “MM” refers to the case when a nucleobase of a first nucleic acid is not capable of pairing with the corresponding nucleobase of a second or target nucleic acid.

“Modified internucleoside linkage” refers to a substitution or any change from a naturally occurring internucleoside bond (i.e. a phosphodiester internucleoside bond).

“Modified nucleobase” refers to any nucleobase other than adenine, cytosine, guanine, thymidine, or uracil. For example, a modified nucleobase can be 5′-methylcytosine. An “unmodified nucleobase” means the purine bases adenine (A) and guanine (G), and the pyrimidine bases thymine (T), cytosine (C), and uracil (U).

“Modified nucleoside” means a nucleoside having, independently, a modified sugar moiety or modified nucleobase.

“Modified nucleotide” means a nucleotide having, independently, a modified sugar moiety, modified internucleoside linkage, or modified nucleobase.

“Modified oligonucleotide” means an oligonucleotide comprising a modified internucleoside linkage, a modified sugar, or a modified nucleobase.

“Modified sugar” refers to a substitution or change from a natural sugar. For example, a modified sugar can be 2′-MOE.

“Modulating” refers to changing or adjusting a feature in a cell, tissue, organ or organism. For example, modulating TMPRSS6 level can mean to increase or decrease the level of TMPRSS6 mRNA or TMPRSS6 protein in a cell, tissue, organ or organism. A “modulator” effects the change in the cell, tissue, organ or organism. For example, a TMPRSS6 antisense oligonucleotide can be a modulator that increases or decreases the amount of TMPRSS6 mRNA or TMPRSS6 protein in a cell, tissue, organ or organism.

“Motif” means the pattern of chemically distinct regions in an antisense compound.

“Mutations” refer to changes in a nucleic acid sequence. Mutations can be caused in a variety of ways including, but not limited to, radiation, viruses, transposons and mutagenic chemicals, as well as errors that occur during meiosis, DNA replication, RNA transcription and post-transcriptional processing. Mutations can result in several different changes in sequence; they can have either no effect, alter the product of a gene, or prevent the gene from functioning properly or completely. For example, HFE mutation can lead to the improper functioning of the gene product, leading to excess iron absorption in the intestines.

“Myelodysplastic syndrome” refers to a diverse collection of hematological medical disease, disorder and/or conditions that involve ineffective production of the myeloid class of blood cells. The syndrome is caused by disorders of the stem cells in the bone marrow. In myelodysplastic syndrome, hematopoiesis is ineffective and the number and quality of blood cells declines irreversibly, further impairing blood production. As a result, patients with myelodysplastic syndrome develop severe anemia and require frequent blood transfusions.

“Naturally occurring internucleoside linkage” means a 3′ to 5′ phosphodiester linkage.

“Natural sugar moiety” means a sugar found in DNA (2′-H) or RNA (2′-OH).

“Nucleic acid” refers to molecules composed of monomeric nucleotides. A nucleic acid includes ribonucleic acids (RNA), deoxyribonucleic acids (DNA), single-stranded nucleic acids, double-stranded nucleic acids, small interfering ribonucleic acids (siRNA), and microRNAs (miRNA).

“Nucleobase” means a heterocyclic moiety capable of pairing with a base of another nucleic acid.

“Nucleobase sequence” means the order of contiguous nucleobases independent of any sugar, linkage, or nucleobase modification.

“Nucleoside” means a nucleobase linked to a sugar.

“Nucleoside mimetic” includes those structures used to replace the sugar or the sugar and the base and not necessarily the linkage at one or more positions of an oligomeric compound; such as, for example, nucleoside mimetics having morpholino, cyclohexenyl, cyclohexyl, tetrahydropyranyl, bicyclo or tricyclo sugar mimetics e.g. non furanose sugar units.

“Nucleotide” means a nucleoside having a phosphate group covalently linked to the sugar portion of the nucleoside.

“Nucleotide mimetic” includes those structures used to replace the nucleoside and the linkage at one or more positions of an oligomeric compound; such as, for example, peptide nucleic acids or morpholinos (morpholinos linked by —N(H)—C(═O)—O— or other non-phosphodiester linkage).

“Oligomeric compound” or “oligomer” refers to a polymeric structure comprising two or more sub-structures and capable of hybridizing to a region of a nucleic acid molecule. In certain embodiments, oligomeric compounds are oligonucleosides. In certain embodiments, oligomeric compounds are oligonucleotides. In certain embodiments, oligomeric compounds are antisense compounds. In certain embodiments, oligomeric compounds are antisense oligonucleotides. In certain embodiments, oligomeric compounds are chimeric oligonucleotides.

“Oligonucleotide” means a polymer of linked nucleosides each of which can be modified or unmodified, independent one from another.

“Parenteral administration” means administration through injection or infusion. Parenteral administration includes subcutaneous administration, intravenous administration, intramuscular administration, intra-arterial administration, intraperitoneal administration, or intracranial administration, e.g. intrathecal or intracerebroventricular administration. Administration can be continuous, or chronic, or short or intermittent.

“Peptide” refers to a molecule formed by linking at least two amino acids by amide bonds. Peptide refers to polypeptides and proteins.

“Percentage saturation of transferrin” refers to the ratio of serum iron to total iron binding capacity multiplied by 100. Of the transferrin molecules that are available to bind iron, this value tells a clinician how much serum iron are actually bound.

“Pharmaceutical composition” means a mixture of substances suitable for administering to an individual. For example, a pharmaceutical composition may comprise one or more active pharmaceutical agents and a sterile aqueous solution.

“Pharmaceutically acceptable carrier” means a medium or diluent that does not interfere with the structure of the oligonucleotide. Certain of such carriers enable pharmaceutical compositions to be formulated as, for example, tablets, pills, dragees, capsules, liquids, gels, syrups, slurries, suspension and lozenges for the oral ingestion by a subject. For example, a pharmaceutically acceptable carrier can be a sterile aqueous solution, such as PBS.

“Pharmaceutically acceptable derivative” encompasses pharmaceutically acceptable salts, conjugates, prodrugs or isomers of the compounds described herein.

“Pharmaceutically acceptable salts” means physiologically and pharmaceutically acceptable salts of antisense compounds, i.e., salts that retain the desired biological activity of the parent oligonucleotide and do not impart undesired toxicological effects thereto.

“Phosphorothioate linkage” means a linkage between nucleosides where the phosphodiester bond is modified by replacing one of the non-bridging oxygen atoms with a sulfur atom. A phosphorothioate linkage is a modified internucleoside linkage.

“Polycythemia” refers to a condition of increased red blood cells (RBCs) in a specified volume due to either an increase in red blood cell numbers (absolute polycythemia) or a decrease in plasma volume (relative polycythemia). Blood volume to red blood cell proportions can be measured as Hematocrit levels. The increased proportion of RBCs can make the blood viscous which can lead to slower blood flow through the circulatory system and potential formation of blood clots. Slower blood flow can decrease oxygen transport to cells, tissue and/or organs leading to diseases, disorders or conditions such as angina or heart failure. Formation of blood clots in the circulatory system can lead to cell, tissue and/or organ damage leading to diseases, disorders or conditions such as myocardial infarction or stroke. Treatment for polycythemia includes phlebotomy or drugs to decrease RBC production (e.g., INF-α, hydroxyurea, anagrelide). Examples of polycythemia include, but is not limited to, polycythemia vera (PCV), polycythemia rubra vera (PRV) and erythremia. In certain instances, polycythemia can progress into erythroid leukemia in a subject.

“Portion” means a defined number of contiguous (i.e. linked) nucleobases of a nucleic acid. In certain embodiments, a portion is a defined number of contiguous nucleobases of a target nucleic acid. In certain embodiments, a portion is a defined number of contiguous nucleobases of an antisense compound.

“Prevent” refers to delaying or forestalling the onset, development, or progression of a disease, disorder, or condition for a period of time from minutes to indefinitely. Prevent also means reducing risk of developing a disease, disorder, or condition.

“Prodrug” means a therapeutic agent that is prepared in an inactive form that is converted to an active form within the body or cells thereof by the action of endogenous enzymes or other chemicals or conditions.

“Side effects” means physiological responses attributable to a treatment other than the desired effects. In certain embodiments, side effects include injection site reactions, liver function test abnormalities, renal function abnormalities, liver toxicity, renal toxicity, central nervous system abnormalities, myopathies, and malaise. For example, increased aminotransferase levels in serum may indicate liver toxicity or liver function abnormality.

“Single-stranded oligonucleotide” means an oligonucleotide which is not hybridized to a complementary strand.

“Specifically hybridizable” refers to an antisense compound having a sufficient degree of complementarity with a target nucleic acid to induce a desired effect, while exhibiting minimal or no effects on non-target nucleic acids under conditions in which specific binding is desired, i.e. under physiological conditions in the case of in vivo assays and therapeutic treatments.

“Subcutaneous administration” means administration just below the skin.

“Targeting” or “targeted” means the process of design and selection of an antisense compound that will specifically hybridize to a target nucleic acid and induce a desired effect.

“Target nucleic acid,” “target RNA,” and “target RNA transcript” all refer to a nucleic acid capable of being targeted by antisense compounds.

“Target segment” means the sequence of nucleotides of a target nucleic acid to which an antisense compound is targeted. “5′ target site” refers to the 5′-most nucleotide of a target segment. “3′ target site” refers to the 3′-most nucleotide of a target segment.

“Thalassemia” refers to a subgroup of anemias (e.g., α-thalassemia, β-thalassemia, δ-thalassemia, non-transfusion dependent thalassemia (NTDT)) caused by the formation of abnormal hemoglobin molecules leading to the destruction or degradation of red blood cells. Complications of thalassemia include excess iron (i.e. iron overload in the blood either from the thalassemia itself or from frequent transfusions to treat the thalassemia), increased risk of infection, bone deformities, enlarged spleens (i.e. splenomegaly), slowed growth rates and heart problems (e.g., congestive heart failure and arrhythmias).

“Therapeutically effective amount” means an amount of a pharmaceutical agent that provides a therapeutic benefit to an individual.

“TMPRSS6” (also known as “matriptase-2”) refers to any nucleic acid or protein of TMPRSS6.

“TMPRSS6 nucleic acid” means any nucleic acid encoding TMPRSS6. For example, in certain embodiments, a TMPRSS6 nucleic acid includes a DNA sequence encoding TMPRSS6, an RNA sequence transcribed from DNA encoding TMPRSS6 (including genomic DNA comprising introns and exons), and a mRNA sequence encoding TMPRSS6. “TMPRSS6 mRNA” means a mRNA encoding a TMPRSS6 protein.

“TMPRSS6 specific inhibitor” refers to any agent capable of specifically inhibiting the expression of TMPRSS6 gene, TMPRSS6 RNA and/or TMPRSS6 protein at the molecular level. For example, TMPRSS6 specific inhibitors include nucleic acids (including antisense compounds), peptides, antibodies, small molecules, and other agents capable of inhibiting the level of TMPRSS6. In certain embodiments, by specifically modulating TMPRSS6, TMPRSS6 specific inhibitors may affect components of the iron accumulation pathway.

“Treat” refers to administering a pharmaceutical composition to an animal in order to effect an alteration or improvement of a disease, disorder, or condition in the animal. In certain embodiments, one or more pharmaceutical compositions can be administered to the animal.

“Unmodified nucleotide” means a nucleotide composed of naturally occuring nucleobases, sugar moieties, and internucleoside linkages. In certain embodiments, an unmodified nucleotide is an RNA nucleotide (i.e. β-D-ribonucleotide) or a DNA nucleotide (i.e. β-D-deoxyribonucleotide).

Certain Embodiments

In certain embodiments, provided herein are TMPRSS6 modulators. In certain embodiments, the TMPRSS6 modulators can be TMPRSS6 specific inhibitors. In certain embodiments, TMPRSS6 specific inhibitors are nucleic acids (including antisense compounds), peptides, antibodies, small molecules, and other agents capable of inhibiting or lowering the expression of TMPRSS6.

In certain embodiments, methods are provided herein for reducing iron accumulation. In certain embodiments, provided are TMPRSS6 inhibitors as described herein for use in reducing iron accumulation in an animal. In certain embodiments, the iron accumulation is the result of a therapy to treat a disease, disorder or condition in the animal. In certain embodiments, the therapy is transfusion therapy. In certain embodiments, the iron accumulation is due to a disease, disorder or condition in the animal. In certain embodiments, the disease, disorder or condition is hereditary hemochromatosis or β-thalassemia. In certain embodiments, the β-thalassemia is β-thalassemia major, β-thalassemia intermedia or β-thalassemia minor.

In certain embodiments, methods are provided herein for increasing hepcidin levels, such as mRNA or protein expression levels. In certain embodiments, provided are TMPRSS6 inhibitors as described herein for use in increasing hepcidin levels, such as mRNA expression levels.

In certain embodiments, methods are provided herein for decreasing the percentage saturation of transferrin in an animal. In certain embodiments, provided are TMPRSS6 inhibitors as described herein for use in decreasing the percentage saturation of transferrin in an animal. In certain embodiments, decreasing transferrin saturation leads to a decrease in iron supply for erythropoiesis. In certain embodiments, the decrease in erythropoiesis treats, prevents, delays the onset of, ameliorates, and/or reduces polycythemia, or symptom thereof, in the animal. In certain embodiments, the polycythemia is polycythemia vera. In certain embodiments, treatment with the modified oligonucleotide targeting TMPRSS6 prevents or delays the polycythemia from progressing into erythroid leukemia.

Methods provided herein comprise administering to the animal a therapeutically effective amount of the TMPRSS6 inhibitor. In certain embodiments, provided are TMPRSS6 inhibitors as described herein for use in administration to an animal in a therapeutically effective amount.

In certain embodiments, methods are provided for treating, preventing, delaying the onset of, ameliorating and/or reducing a disease, disorder and/or condition, or symptom thereof, associated with the excess accumulation of iron in an animal, comprising administering to the animal a therapeutically effective amount of a TMPRSS6 inhibitor, wherein the disease, disorder and/or condition associated with excess iron accumulation is treated, prevented, the onset delayed, the symptom ameliorated or reduced.

In certain embodiments, methods are provided for treating, preventing, delaying the onset of, ameliorating, and/or reducing hereditary hemochromatosis, or symptom thereof, in an animal, comprising administering to the animal a therapeutically effective amount of a modified oligonucleotide targeting TMPRSS6, wherein the modified oligonucleotide comprises (a) a gap segment consisting of linked deoxy nucleosides (b) a 5′ wing segment consisting of linked nucleosides (c) a 3′ wing segment consisting of linked nucleosides, and wherein the gap segment is positioned between the 5′ wing segment and the 3′ wing segment and wherein each nucleoside of each wing segment comprises a modified sugar.

In certain embodiments, methods are provided for treating, preventing, delaying the onset of, ameliorating, and/or reducing anemia, or symptom thereof, in an animal, comprising administering to the animal a therapeutically effective amount of a modified oligonucleotide targeting TMPRSS6, wherein the modified oligonucleotide comprises (a) a gap segment consisting of linked deoxy nucleosides (b) a 5′ wing segment consisting of linked nucleosides (c) a 3′ wing segment consisting of linked nucleosides, and wherein the gap segment is positioned between the 5′ wing segment and the 3′ wing segment and wherein each nucleoside of each wing segment comprises a modified sugar.

In certain embodiments, methods are provided for treating, preventing, delaying the onset of, ameliorating, and/or reducing β-thalassemia, or symptom thereof, in an animal, comprising administering to the animal a therapeutically effective amount of a modified oligonucleotide targeting TMPRSS6, wherein the modified oligonucleotide comprises (a) a gap segment consisting of linked deoxy nucleosides (b) a 5′ wing segment consisting of linked nucleosides (c) a 3′ wing segment consisting of linked nucleosides, and wherein the gap segment is positioned between the 5′ wing segment and the 3′ wing segment and wherein each nucleoside of each wing segment comprises a modified sugar.

In certain embodiments, methods are provided for decreasing transferrin saturation in an animal, comprising administering to the animal a therapeutically effective amount of a modified oligonucleotide targeting TMPRSS6, wherein the modified oligonucleotide comprises (a) a gap segment consisting of linked deoxy nucleosides (b) a 5′ wing segment consisting of linked nucleosides (c) a 3′ wing segment consisting of linked nucleosides, and wherein the gap segment is positioned between the 5′ wing segment and the 3′ wing segment and wherein each nucleoside of each wing segment comprises a modified sugar. In certain embodiments, decreasing transferrin saturation leads to a decrease in iron supply for erythropoiesis. In certain embodiments, the decrease in erythropoiesis treats, prevents, delays the onset of, ameliorates, and/or reduces polycythemia, or symptom thereof, in the animal. In certain embodiments, the polycythemia is polycythemia vera. In certain embodiments, treatment with the modified oligonucleotide targeting TMPRSS6 prevents or delays the polycythemia from progressing into erythroid leukemia.

In certain embodiments, methods are provided for identifying an animal at risk for a disease, disorder and/or condition or having a disease, disorder and/or condition which is associated with excess accumulation of iron, administering to the animal a therapeutically effective amount of a TMPRSS6 inhibitor, thereby treating the animal.

In certain embodiments, provided herein is the use of a TMPRSS6 inhibitor for the preparation of a medicament. In certain embodiments, are provided TMPRSS6 inhibitors as described herein for use in the preparation of a medicament.

In certain embodiments, provided herein is the use of a TMPRSS6 inhibitor as a medicament for treating, preventing, delaying the onset of, and/or reducing a disease, disorder and/or condition, or symptom thereof, associated with excess accumulation of iron in an animal by administering to the animal a therapeutically effective amount of the TMPRSS6 inhibitor. In certain embodiments are provided TMPRSS6 inhibitors as described herein for use in treating, preventing, delaying the onset of, and/or reducing a disease, disorder and/or condition, or symptom thereof, associated with excess accumulation of iron in an animal.

In certain embodiments, provided herein is the use of a TMPRSS6 antisense compound for inhibiting TMPRSS6. In certain embodiments, provided herein is a TMPRSS6 antisense compound for use in inhibiting TMPRSS6.

In certain embodiments, the disease is hemochromatosis. In certain embodiments, the disease is associated with mutations in the HFE gene. In other embodiments, the disease is associated with mutations in the hemojuvelin gene. In other embodiments, the disease is associated with mutations in the hepcidin gene.

In certain embodiments, provided herein is the use of a TMPRSS6 inhibitor as a medicament for treating, preventing, delaying the onset of, and/or reducing polycythemia or erythoid leukemia. In certain embodiments are provided TMPRSS6 inhibitors as described herein for use in treating, preventing, delaying the onset of, and/or reducing polycythemia or erythoid leukemia. In certain embodiments, the polycythemia includes, but is not limited to, polycythemia vera (PCV), polycythemia rubra vera (PRV) and erythremia

In certain embodiments, the disease, disorder and/or condition may be due to multiple blood transfusions. In certain embodiments, multiple transfusions may lead to polycythemia. In further embodiments, multiple blood transfusions are associated with the animal having anemia. Examples of anemia requiring multiple blood transfusions are hereditary anemia, myelodysplastic syndrome and severe chronic hemolysis. Examples of hereditary anemia include, but are not limited to, sickle cell anemia, thalassemia, Fanconi anemia, Diamond Blackfan anemia, Shwachman Diamond syndrome, red cell membrane disorders, glucose-6-phosphate dehydrogenase deficiency, or hereditary hemorrhagic telangiectasia. In certain embodiments, the thalassemia is β-thalassemia. In certain embodiments, the β-thalassemia is β-thalassemia major, β-thalassemia intermedia or β-thalassemia minor. In certain embodiments, the disease, disorder and/or condition is associated with excess parenteral iron supplement intake or excess dietary iron intake.

In certain embodiments, provided herein are compounds targeted to a TMPRSS6 nucleic acid. In certain embodiments, the TMPRSS6 nucleic acid is the murine sequence set forth in GENBANK Accession No. NM_027902.2 (incorporated herein as SEQ ID NO: 1). In certain embodiments, the TMPRSS6 nucleic acid is any of the human sequences set forth in GENBANK Accession No. NM_153609.2 (incorporated herein as SEQ ID NO: 2), the complement of GENBANK Accession No. NT_011520.12 truncated from 16850000 to 16891250 (incorporated herein as SEQ ID NO: 3), GENBANK Accession No. CR456446.1 (incorporated herein as SEQ ID NO: 4), GENBANK Accession No. BC039082.1 (incorporated herein as SEQ ID NO: 5), GENBANK Accession No. AY358398.1 (incorporated herein as SEQ ID NO: 6), or GENBANK Accession No. DB081153.1 (incorporated herein as SEQ ID NO: 7).

In certain embodiments, the TMPRSS6 nucleic acid is a modified oligonucleotide. In certain embodiments, TMPRSS6 nucleic acid consists of 12 to 30, 10 to 30, 8 to 80, 10 to 50, 15 to 30, 18 to 21, 20 to 80, 20 to 35, 20 to 30, 20 to 29, 20 to 28, 20 to 27, 20 to 26, 20 to 25, 20 to 24, 20 to 23, 20 to 22, 20 to 21 or 20 linked nucleobases. In certain such embodiments, the antisense compound comprises a modified oligonucleotide consisting of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80 linked nucleobases in length, or a range defined by any two of the above values. In further embodiments, the modified oligonucleotide is single-stranded.

In certain embodiments, the compound for use in the methods can comprise a modified oligonucleotide comprising a nucleobase sequence at least 70%, at least 75%, at least 80%, at least 85%, 90%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% complementary to an equal length portion of SEQ ID NOs: 1-7. In certain embodiments, the compound can comprise a modified oligonucleotide comprising a nucleobase sequence 100% complementary to an equal length portion of SEQ ID NOs: 1-7.

In certain embodiments, provided are compounds for use in the methods comprising a modified oligonucleotide having a nucleobase sequence comprising at least 8, at least 9, at least 10, at least 11, at least 12, at least 13, at least 14, at least 15, at least 16, at least 17, at least 18, at least 19 or at least 20 contiguous nucleobases of a nucleobase sequence complementary to any of the sequences recited in SEQ ID NOs: 1-7.

In certain embodiments, the modified oligonucleotide for use in the methods consists of TMPRSS6 nucleic acid consists of 12 to 30, 10 to 30, 8 to 80, 10 to 50, 15 to 30, 18 to 21, 20 to 80, 20 to 35, 20 to 30, 20 to 29, 20 to 28, 20 to 27, 20 to 26, 20 to 25, 20 to 24, 20 to 23, 20 to 22, 20 to 21 or 20 linked nucleobases. In certain such embodiments, the antisense compound comprises a modified oligonucleotide consisting of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80 linked nucleobases in length, or a range defined by any two of the above values.

In certain embodiments, the compound for use in the methods has at least one modified internucleoside linkage. In certain embodiments, the modified internucleoside linkage is a phosphorothioate internucleoside linkage

In certain embodiments, the compound for use in the methods has at least one nucleoside comprising a modified sugar. In certain embodiments, at least one modified sugar is a bicyclic sugar.

In certain embodiments, the compound for use in the methods has at least one nucleoside comprising a modified nucleobase. In certain embodiments, the modified nucleobase is a 5-methylcytosine.

In certain embodiments, the modified oligonucleotide of the compound for use in the methods comprises: (i) a gap segment consisting of linked deoxynucleosides; (ii) a 5′ wing segment consisting of linked nucleosides; (iii) a 3′ wing segment consisting of linked nucleosides, wherein the gap segment is positioned immediately adjacent to and between the 5′ wing segment and the 3′ wing segment and wherein each nucleoside of each wing segment comprises a modified sugar. In certain embodiments, the modified oligonucleotide further comprises at least one phosphorothioate internucleoside linkage.

In certain embodiments, provided are methods or uses wherein the animal is human.

In certain embodiments, the administering of a TMPRSS6 inhibitor reduces accumulation of iron in the animal. In certain embodiments, the TMPRSS6 inhibitor increases hepcidin expression levels. In other embodiments, the TMPRSS6 inhibitor decreases the percentage of saturation of transferrin.

In certain embodiments, the compound is co-administered with one or more second agent(s). In certain embodiments the second agent is an iron chelator or a hepcidin agonist. In further embodiments, the iron chelator includes FBS0701 (FerroKin), Exjade, Desferal or Deferiprone. In certain embodiments, the second agent is a second antisense compound. In further embodiments, the second antisense compound targets TMPRSS6. In other embodiments, the second antisense compound targets a non-TMPRSS6 compound. In other embodiments, the TMPRSS6 inhibitor is administered before, during or after phlebotomy therapy.

Antisense Compounds

Oligomeric compounds include, but are not limited to, oligonucleotides, oligonucleosides, oligonucleotide analogs, oligonucleotide mimetics, antisense compounds, antisense oligonucleotides, and siRNAs. An oligomeric compound can be “antisense” to a target nucleic acid, meaning that it is capable of undergoing hybridization to a target nucleic acid through hydrogen bonding.

In certain embodiments, an antisense compound has a nucleobase sequence that, when written in the 5′ to 3′ direction, comprises the reverse complement of the target segment of a target nucleic acid to which it is targeted. In certain such embodiments, an antisense oligonucleotide has a nucleobase sequence that, when written in the 5′ to 3′ direction, comprises the reverse complement of the target segment of a target nucleic acid to which it is targeted.

In certain embodiments, an antisense compound targeted to TMPRSS6 nucleic acid is 10 to 30 nucleotides in length. In other words, antisense compounds are from 10 to 30 linked nucleobases. In other embodiments, the antisense compound comprises a modified oligonucleotide consisting of 8 to 80, 10 to 80, 12 to 50, 15 to 30, 18 to 24, 19 to 22, or 20 linked nucleobases. In certain such embodiments, the antisense compound comprises a modified oligonucleotide consisting of 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, or 80 linked nucleobases in length, or a range defined by any two of the above values. In some embodiments, the antisense compound is an antisense oligonucleotide.

In certain embodiments, the antisense compound comprises a shortened or truncated modified oligonucleotide. The shortened or truncated modified oligonucleotide can have a single nucleoside deleted from the 5′ end (5′ truncation), the central portion or alternatively from the 3′ end (3′ truncation). A shortened or truncated oligonucleotide can have two or more nucleosides deleted from the 5′ end, two or more nucleosides deleted from the central portion or alternatively can have two or more nucleosides deleted from the 3′ end. Alternatively, the deleted nucleosides can be dispersed throughout the modified oligonucleotide, for example, in an antisense compound having one or more nucleoside deleted from the 5′ end, one or more nucleoside deleted from the central portion and/or one or more nucleoside deleted from the 3′ end.

When a single additional nucleoside is present in a lengthened oligonucleotide, the additional nucleoside can be located at the 5′ end, 3′ end or central portion of the oligonucleotide. When two or more additional nucleosides are present, the added nucleosides can be adjacent to each other, for example, in an oligonucleotide having two nucleosides added to the 5′ end (5′ addition), to the 3′ end (3′ addition) or the central portion, of the oligonucleotide. Alternatively, the added nucleoside can be dispersed throughout the antisense compound, for example, in an oligonucleotide having one or more nucleoside added to the 5′ end, one or more nucleoside added to the 3′ end, and/or one or more nucleoside added to the central portion.

It is possible to increase or decrease the length of an antisense compound, such as an antisense oligonucleotide, and/or introduce mismatch bases without eliminating activity. For example, in Woolf et al. (Proc. Natl. Acad. Sci. USA 89:7305-7309, 1992), a series of antisense oligonucleotides 13-25 nucleobases in length were tested for their ability to induce cleavage of a target RNA in an oocyte injection model. Antisense oligonucleotides 25 nucleobases in length with 8 or 11 mismatch bases near the ends of the antisense oligonucleotides were able to direct specific cleavage of the target mRNA, albeit to a lesser extent than the antisense oligonucleotides that contained no mismatches. Similarly, target specific cleavage was achieved using 13 nucleobase antisense oligonucleotides, including those with 1 or 3 mismatches.

Gautschi et al (J. Natl. Cancer Inst. 93:463-471, March 2001) demonstrated the ability of an oligonucleotide having 100% complementarity to the bcl-2 mRNA and having 3 mismatches to the bcl-xL mRNA to reduce the expression of both bcl-2 and bcl-xL in vitro and in vivo. Furthermore, this oligonucleotide demonstrated potent anti-tumor activity in vivo.

Maher and Dolnick (Nuc. Acid. Res. 16:3341-3358, 1988) tested a series of tandem 14 nucleobase antisense oligonucleotides, and a 28 and 42 nucleobase antisense oligonucleotides comprised of the sequence of two or three of the tandem antisense oligonucleotides, respectively, for their ability to arrest translation of human DHFR in a rabbit reticulocyte assay. Each of the three 14 nucleobase antisense oligonucleotides alone was able to inhibit translation, albeit at a more modest level than the 28 or 42 nucleobase antisense oligonucleotides.

Antisense Compound Motifs

In certain embodiments, antisense compounds targeted to a TMPRSS6 nucleic acid have chemically modified subunits arranged in patterns, or motifs, to confer to the antisense compounds properties such as enhanced the inhibitory activity, increased binding affinity for a target nucleic acid, or resistance to degradation by in vivo nucleases.

Chimeric antisense compounds typically contain at least one region modified so as to confer increased resistance to nuclease degradation, increased cellular uptake, increased binding affinity for the target nucleic acid, and/or increased inhibitory activity. A second region of a chimeric antisense compound can optionally serve as a substrate for the cellular endonuclease RNase H, which cleaves the RNA strand of a RNA:DNA duplex.

Antisense compounds having a gapmer motif are considered chimeric antisense compounds. In a gapmer an internal region having a plurality of nucleotides that supports RNase H cleavage is positioned between external regions having a plurality of nucleotides that are chemically distinct from the nucleosides of the internal region. In the case of an antisense oligonucleotide having a gapmer motif, the gap segment generally serves as the substrate for endonuclease cleavage, while the wing segments comprise modified nucleosides. In certain embodiments, the regions of a gapmer are differentiated by the types of sugar moieties comprising each distinct region. The types of sugar moieties that are used to differentiate the regions of a gapmer can in some embodiments include β-D-ribonucleosides, β-D-deoxyribonucleosides, 2′-modified nucleosides (such 2′-modified nucleosides can include 2′-MOE, and 2′-O—CH₃, among others), and bicyclic sugar modified nucleosides (such bicyclic sugar modified nucleosides can include those having a 4′-(CH2)n-O-2′ bridge, where n=1 or n=2). Preferably, each distinct region comprises uniform sugar moieties. The wing-gap-wing motif is frequently described as “X—Y—Z”, where “X” represents the length of the 5′ wing region, “Y” represents the length of the gap region, and “Z” represents the length of the 3′ wing region. As used herein, a gapmer described as “X—Y—Z” has a configuration such that the gap segment is positioned immediately adjacent each of the 5′ wing segment and the 3′ wing segment. Thus, no intervening nucleotides exist between the 5′ wing segment and gap segment, or the gap segment and the 3′ wing segment. Any of the antisense compounds described herein can have a gapmer motif. In some embodiments, X and Z are the same; in other embodiments they are different. In a preferred embodiment, Y is between 8 and 15 nucleotides. X, Y or Z can be any of 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 or more nucleotides. Thus, gapmers include, but are not limited to, for example 5-10-5, 4-8-4, 4-12-3, 4-12-4, 3-14-3, 2-13-5, 2-16-2, 1-18-1, 3-10-3, 2-10-2, 1-10-1, 2-8-2, 6-8-6, 5-8-5, 1-8-1, 2-6-2, 6-8-6, 5-8-5, 1-8-1, 2-6-2, 2-13-2, 1-8-2, 2-8-3, 3-10-2, 1-18-2, or 2-18-2.

In certain embodiments, the antisense compound as a “wingmer” motif, having a wing-gap or gap-wing configuration, i.e. an X—Y or Y—Z configuration as described above for the gapmer configuration. Thus, wingmer configurations include, but are not limited to, for example 5-10, 8-4, 4-12, 12-4, 3-14, 16-2, 18-1, 10-3, 2-10, 1-10, 8-2, 2-13, or 5-13.

Target Nucleic Acids, Target Regions and Nucleotide Sequences

Nucleotide sequences that encode TMPRSS6 include, without limitation, the following: GENBANK Accession No. NM_027902.2 (incorporated herein as SEQ ID NO: 1), GENBANK Accession NM_153609.2 (incorporated herein as SEQ ID NO: 2), the complement of GENBANK Accession NT_011520.12 truncated from 16850000 to 16891250 (incorporated herein as SEQ ID NO: 3), GENBANK Accession CR456446.1 (incorporated herein as SEQ ID NO: 4), GENBANK Accession No. BC039082.1 (incorporated herein as SEQ ID NO: 5), GENBANK Accession No. AY358398.1 (incorporated herein as SEQ ID NO: 6), or GENBANK Accession No. DB081153.1 (incorporated herein as SEQ ID NO: 7).

It is understood that the sequence set forth in each SEQ ID NO in the examples contained herein is independent of any modification to a sugar moiety, an internucleoside linkage, or a nucleobase. As such, antisense compounds defined by a SEQ ID NO may comprise, independently, one or more modifications to a sugar moiety, an internucleoside linkage, or a nucleobase. Antisense compounds described by Isis Number (Isis No) indicate a combination of nucleobase sequence and motif.

In certain embodiments, a target region is a structurally defined region of the target nucleic acid. For example, a target region may encompass a 3′ UTR, a 5′ UTR, an exon, an intron, an exon/intron junction, a coding region, a translation initiation region, translation termination region, or other defined nucleic acid region. The structurally defined regions for TMPRSS6 can be obtained by accession number from sequence databases such as NCBI and such information is incorporated herein by reference. In certain embodiments, a target region may encompass the sequence from a 5′ target site of one target segment within the target region to a 3′ target site of another target segment within the target region.

In certain embodiments, a “target segment” is a smaller, sub-portion of a target region within a nucleic acid. For example, a target segment can be the sequence of nucleotides of a target nucleic acid to which one or more antisense compound is targeted. “5′ target site” refers to the 5′-most nucleotide of a target segment. “3′ target site” refers to the 3′-most nucleotide of a target segment.

Targeting includes determination of at least one target segment to which an antisense compound hybridizes, such that a desired effect occurs. In certain embodiments, the desired effect is a reduction in mRNA target nucleic acid levels. In certain embodiments, the desired effect is reduction of levels of protein encoded by the target nucleic acid or a phenotypic change associated with the target nucleic acid.

A target region may contain one or more target segments. Multiple target segments within a target region may be overlapping. Alternatively, they may be non-overlapping. In certain embodiments, target segments within a target region are separated by no more than about 300 nucleotides. In certain embodiments, target segments within a target region are separated by a number of nucleotides that is, is about, is no more than, is no more than about, 250, 200, 150, 100, 90, 80, 70, 60, 50, 40, 30, 20, or 10 nucleotides on the target nucleic acid, or is a range defined by any two of the preceeding values. In certain embodiments, target segments within a target region are separated by no more than, or no more than about, 5 nucleotides on the target nucleic acid. In certain embodiments, target segments are contiguous. Contemplated are target regions defined by a range having a starting nucleic acid that is any of the 5′ target sites or 3′ target sites listed herein.

Suitable target segments may be found within a 5′ UTR, a coding region, a 3′ UTR, an intron, an exon, or an exon/intron junction. Target segments containing a start codon or a stop codon are also suitable target segments. A suitable target segment may specifically exclude a certain structurally defined region such as the start codon or stop codon.

The determination of suitable target segments may include a comparison of the sequence of a target nucleic acid to other sequences throughout the genome. For example, the BLAST algorithm may be used to identify regions of similarity amongst different nucleic acids. This comparison can prevent the selection of antisense compound sequences that may hybridize in a non-specific manner to sequences other than a selected target nucleic acid (i.e., non-target or off-target sequences).

There may be variation in activity (e.g., as defined by percent reduction of target nucleic acid levels) of the antisense compounds within an active target region. In certain embodiments, reductions in TMPRSS6 mRNA levels are indicative of inhibition of TMPRSS6 expression. Reductions in levels of a TMPRSS6 protein are also indicative of inhibition of TMPRSS6 expression. Further, phenotypic changes are indicative of inhibition of TMPRSS6 expression. For example, an increase in hepcidin expression levels can be indicative of inhibition of TMPRSS6 expression. In another example, a decrease in iron accumulation in tissues can be indicative of inhibition of TMPRSS6 expression. In another example, an increase in the percentage of saturation of transferrin can be indicative of inhibition of TMPRSS6 expression.

Hybridization

In some embodiments, hybridization occurs between an antisense compound disclosed herein and a TMPRSS6 nucleic acid. The most common mechanism of hybridization involves hydrogen bonding (e.g., Watson-Crick, Hoogsteen or reversed Hoogsteen hydrogen bonding) between complementary nucleobases of the nucleic acid molecules.

Hybridization can occur under varying conditions. Stringent conditions are sequence-dependent and are determined by the nature and composition of the nucleic acid molecules to be hybridized.

Methods of determining whether a sequence is specifically hybridizable to a target nucleic acid are well known in the art (Sambrook and Russell, Molecular Cloning: A Laboratory Manual, 3^(rd) Ed., 2001). In certain embodiments, the antisense compounds provided herein are specifically hybridizable with a TMPRSS6 nucleic acid.

Complementarity

An antisense compound and a target nucleic acid are complementary to each other when a sufficient number of nucleobases of the antisense compound can hydrogen bond with the corresponding nucleobases of the target nucleic acid, such that a desired effect will occur (e.g., antisense inhibition of a target nucleic acid, such as a TMPRSS6 nucleic acid).

Non-complementary nucleobases between an antisense compound and a TMPRSS6 nucleic acid may be tolerated provided that the antisense compound remains able to specifically hybridize to a target nucleic acid. Moreover, an antisense compound may hybridize over one or more segments of a TMPRSS6 nucleic acid such that intervening or adjacent segments are not involved in the hybridization event (e.g., a loop structure, mismatch or hairpin structure).

In certain embodiments, the antisense compounds provided herein, or a specified portion thereof, are, or are at least, 70%, 80%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% complementary to a TMPRSS6 nucleic acid, a target region, target segment, or specified portion thereof. Percent complementarity of an antisense compound with a target nucleic acid can be determined using routine methods. For example, an antisense compound in which 18 of 20 nucleobases of the antisense compound are complementary to a target region, and would therefore specifically hybridize, would represent 90 percent complementarity. In this example, the remaining noncomplementary nucleobases may be clustered or interspersed with complementary nucleobases and need not be contiguous to each other or to complementary nucleobases. As such, an antisense compound which is 18 nucleobases in length having 4 (four) noncomplementary nucleobases which are flanked by two regions of complete complementarity with the target nucleic acid would have 77.8% overall complementarity with the target nucleic acid and would thus fall within the scope of the present invention.

Percent complementarity of an antisense compound with a region of a target nucleic acid can be determined routinely using BLAST programs (basic local alignment search tools) and PowerBLAST programs known in the art (Altschul et al., J. Mol. Biol., 1990, 215, 403 410; Zhang and Madden, Genome Res., 1997, 7, 649 656). Percent homology, sequence identity or complementarity, can be determined by, for example, the Gap program (Wisconsin Sequence Analysis Package, Version 8 for Unix, Genetics Computer Group, University Research Park, Madison Wis.), using default settings, which uses the algorithm of Smith and Waterman (Adv. Appl. Math., 1981, 2, 482 489).

In certain embodiments, the antisense compounds provided herein, or specified portions thereof, are fully complementary (i.e. 100% complementary) to a target nucleic acid, or specified portion thereof. For example, antisense compound may be fully complementary to a TMPRSS6 nucleic acid, or a target region, or a target segment or target sequence thereof. As used herein, “fully complementary” means each nucleobase of an antisense compound is capable of precise base pairing with the corresponding nucleobases of a target nucleic acid. For example, a 20 nucleobase antisense compound is fully complementary to a target sequence that is 400 nucleobases long, so long as there is a corresponding 20 nucleobase portion of the target nucleic acid that is fully complementary to the antisense compound. Fully complementary can also be used in reference to a specified portion of the first and/or the second nucleic acid. For example, a 20 nucleobase portion of a 30 nucleobase antisense compound can be “fully complementary” to a target sequence that is 400 nucleobases long. The 20 nucleobase portion of the 30 nucleobase oligonucleotide is fully complementary to the target sequence if the target sequence has a corresponding 20 nucleobase portion wherein each nucleobase is complementary to the 20 nucleobase portion of the antisense compound. At the same time, the entire 30 nucleobase antisense compound may or may not be fully complementary to the target sequence, depending on whether the remaining 10 nucleobases of the antisense compound are also complementary to the target sequence.

The location of a non-complementary nucleobase may be at the 5′ end or 3′ end of the antisense compound. Alternatively, the non-complementary nucleobase or nucleobases may be at an internal position of the antisense compound. When two or more non-complementary nucleobases are present, they may be contiguous (i.e. linked) or non-contiguous. In one embodiment, a non-complementary nucleobase is located in the wing segment of a gapmer antisense oligonucleotide.

In certain embodiments, antisense compounds that are, or are up to, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleobases in length comprise no more than 4, no more than 3, no more than 2, or no more than 1 non-complementary nucleobase(s) relative to a target nucleic acid, such as a TMPRSS6 nucleic acid, or specified portion thereof.

In certain embodiments, antisense compounds that are, or are up to, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, or 30 nucleobases in length comprise no more than 6, no more than 5, no more than 4, no more than 3, no more than 2, or no more than 1 non-complementary nucleobase(s) relative to a target nucleic acid, such as a TMPRSS6 nucleic acid, or specified portion thereof.

The antisense compounds provided herein also include those which are complementary to a portion of a target nucleic acid. As used herein, “portion” refers to a defined number of contiguous (i.e. linked) nucleobases within a region or segment of a target nucleic acid. A “portion” can also refer to a defined number of contiguous nucleobases of an antisense compound. In certain embodiments, the antisense compounds, are complementary to at least an 8 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 12 nucleobase portion of a target segment. In certain embodiments, the antisense compounds are complementary to at least a 15 nucleobase portion of a target segment. Also contemplated are antisense compounds that are complementary to at least a 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, or more nucleobase portion of a target segment, or a range defined by any two of these values.

Identity

The antisense compounds provided herein may also have a defined percent identity to a particular nucleotide sequence, SEQ ID NO, or compound represented by a specific Isis number, or portion thereof. As used herein, an antisense compound is identical to the sequence disclosed herein if it has the same nucleobase pairing ability. For example, a RNA which contains uracil in place of thymidine in a disclosed DNA sequence would be considered identical to the DNA sequence since both uracil and thymidine pair with adenine. Shortened and lengthened versions of the antisense compounds described herein as well as compounds having non-identical bases relative to the antisense compounds provided herein also are contemplated. The non-identical bases may be adjacent to each other or dispersed throughout the antisense compound. Percent identity of an antisense compound is calculated according to the number of bases that have identical base pairing relative to the sequence to which it is being compared.

In certain embodiments, the antisense compounds, or portions thereof, are at least 70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identical to one or more of the antisense compounds or SEQ ID NOs, or a portion thereof, disclosed herein.

Modifications

A nucleoside is a base-sugar combination. The nucleobase (also known as base) portion of the nucleoside is normally a heterocyclic base moiety. Nucleotides are nucleosides that further include a phosphate group covalently linked to the sugar portion of the nucleoside. For those nucleosides that include a pentofuranosyl sugar, the phosphate group can be linked to the 2′, 3′ or 5′ hydroxyl moiety of the sugar. Oligonucleotides are formed through the covalent linkage of adjacent nucleosides to one another, to form a linear polymeric oligonucleotide. Within the oligonucleotide structure, the phosphate groups are commonly referred to as forming the internucleoside linkages of the oligonucleotide.

Modifications to antisense compounds encompass substitutions or changes to internucleoside linkages, sugar moieties, or nucleobases. Modified antisense compounds are often preferred over native forms because of desirable properties such as, for example, enhanced cellular uptake, enhanced affinity for nucleic acid target, increased stability in the presence of nucleases, or increased inhibitory activity.

Chemically modified nucleosides may also be employed to increase the binding affinity of a shortened or truncated antisense oligonucleotide for its target nucleic acid. Consequently, comparable results can often be obtained with shorter antisense compounds that have such chemically modified nucleosides.

Modified Internucleoside Linkages

The naturally occuring internucleoside linkage of RNA and DNA is a 3′ to 5′ phosphodiester linkage. Antisense compounds having one or more modified, i.e. non-naturally occurring, internucleoside linkages are often selected over antisense compounds having naturally occurring internucleoside linkages because of desirable properties such as, for example, enhanced cellular uptake, enhanced affinity for target nucleic acids, and increased stability in the presence of nucleases.

Oligonucleotides having modified internucleoside linkages include internucleoside linkages that retain a phosphorus atom as well as internucleoside linkages that do not have a phosphorus atom. Representative phosphorus containing internucleoside linkages include, but are not limited to, phosphodiesters, phosphotriesters, methylphosphonates, phosphoramidate, and phosphorothioates. Methods of preparation of phosphorous-containing and non-phosphorous-containing linkages are well known.

In certain embodiments, antisense compounds targeted to a TMPRSS6 nucleic acid comprise one or more modified internucleoside linkages. In certain embodiments, the modified internucleoside linkages are phosphorothioate linkages. In certain embodiments, each internucleoside linkage of an antisense compound is a phosphorothioate internucleoside linkage.

Modified Sugar Moieties

Antisense compounds can optionally contain one or more nucleosides wherein the sugar group has been modified. Such sugar modified nucleosides may impart enhanced nuclease stability, increased binding affinity, or some other beneficial biological property to the antisense compounds. In certain embodiments, nucleosides comprise chemically modified ribofuranose ring moieties. Examples of chemically modified ribofuranose rings include without limitation, addition of substitutent groups (including 5′ and 2′ substituent groups, bridging of non-geminal ring atoms to form bicyclic nucleic acids (BNA), replacement of the ribosyl ring oxygen atom with S, N(R), or C(R₁)(R₂) (R, R₁ and R₂ are each independently H, C₁-C₁₂ alkyl or a protecting group) and combinations thereof. Examples of chemically modified sugars include 2′-F-5′-methyl substituted nucleoside (see PCT International Application WO 2008/101157 Published on Aug. 21, 2008 for other disclosed 5′,2′-bis substituted nucleosides) or replacement of the ribosyl ring oxygen atom with S with further substitution at the 2′-position (see published U.S. Patent Application US2005-0130923, published on Jun. 16, 2005) or alternatively 5′-substitution of a BNA (see PCT International Application WO 2007/134181 Published on Nov. 22, 2007 wherein LNA is substituted with for example a 5′-methyl or a 5′-vinyl group).

Examples of nucleosides having modified sugar moieties include without limitation nucleosides comprising 5′-vinyl, 5′-methyl (R or S), 4′-S, 2′-F, 2′-OCH₃, 2′-OCH₂CH₃, 2′-OCH₂CH₂F and 2′-O(CH₂)₂OCH₃ substituent groups. The substituent at the 2′ position can also be selected from allyl, amino, azido, thio, O-allyl, O—C₁-C₁₀ alkyl, OCF₃, OCH₂F, O(CH₂)₂SCH₃, O(CH₂)₂—O—N(R_(m))(R_(n)), O—CH₂—C(═O)—N(R_(m))(R_(n)), and O—CH₂—C(═O)—N(R₁)—(CH₂)₂—N(R_(m))(R_(n)), where each R_(l), R_(m) and R_(n) is, independently, H or substituted or unsubstituted C₁-C₁₀ alkyl.

As used herein, “bicyclic nucleosides” refer to modified nucleosides comprising a bicyclic sugar moiety. Examples of bicyclic nucleosides include without limitation nucleosides comprising a bridge between the 4′ and the 2′ ribosyl ring atoms. In certain embodiments, antisense compounds provided herein include one or more bicyclic nucleosides comprising a 4′ to 2′ bridge. Examples of such 4′ to 2′ bridged bicyclic nucleosides, include but are not limited to one of the formulae: 4′-(CH₂)—O-2′ (LNA); 4′-(CH₂)—S-2′; 4′-(CH₂)₂—O-2′ (ENA); 4′-CH(CH₃)—O-2′ and 4′-CH(CH₂OCH₃)—O-2′ (and analogs thereof see U.S. Pat. No. 7,399,845, issued on Jul. 15, 2008); 4′-C(CH₃)(CH₃)—O-2′ (and analogs thereof see published International Application WO/2009/006478, published Jan. 8, 2009); 4′-CH₂—N(OCH₃)-2′ (and analogs thereof see published International Application WO/2008/150729, published Dec. 11, 2008); 4′-CH₂—O—N(CH₃)-2′ (see published U.S. Patent Application US 2004-0171570, published Sep. 2, 2004); 4′-CH₂—N(R)—O-2′, wherein R is H, C₁-C₁₂ alkyl, or a protecting group (see U.S. Pat. No. 7,427,672, issued on Sep. 23, 2008); 4′-CH₂—C(H)(CH₃)-2′ (see Chattopadhyaya et al., J. Org. Chem., 2009, 74, 118-134); and 4′-CH₂—C(═CH₂)-2′ (and analogs thereof see published International Application WO 2008/154401, published on Dec. 8, 2008).

Further reports related to bicyclic nucleosides can also be found in published literature (see for example: Singh et al., Chem. Commun., 1998, 4, 455-456; Koshkin et al., Tetrahedron, 1998, 54, 3607-3630; Wahlestedt et al., Proc. Natl. Acad. Sci. U.S.A., 2000, 97, 5633-5638; Kumar et al., Bioorg. Med. Chem. Lett., 1998, 8, 2219-2222; Singh et al., J. Org. Chem., 1998, 63, 10035-10039; Srivastava et al., J. Am. Chem. Soc., 2007, 129(26) 8362-8379; Elayadi et al., Curr. Opinion Invest. Drugs, 2001, 2, 558-561; Braasch et al., Chem. Biol., 2001, 8, 1-7; and Orum et al., Curr. Opinion Mol. Ther., 2001, 3, 239-243; U.S. Pat. Nos. 6,268,490; 6,525,191; 6,670,461; 6,770,748; 6,794,499; 7,034,133; 7,053,207; 7,399,845; 7,547,684; and 7,696,345; U.S. Patent Publication No. US2008-0039618; US2009-0012281; U.S. Patent Ser. Nos. 60/989,574; 61/026,995; 61/026,998; 61/056,564; 61/086,231; 61/097,787; and 61/099,844; Published PCT International applications WO 1994/014226; WO 2004/106356; WO 2005/021570; WO 2007/134181; WO 2008/150729; WO 2008/154401; and WO 2009/006478. Each of the foregoing bicyclic nucleosides can be prepared having one or more stereochemical sugar configurations including for example α-L-ribofuranose and β-D-ribofuranose (see PCT international application PCT/DK98/00393, published on Mar. 25, 1999 as WO 99/14226).

In certain embodiments, bicyclic sugar moieties of BNA nucleosides include, but are not limited to, compounds having at least one bridge between the 4′ and the 2′ position of the pentofuranosyl sugar moiety wherein such bridges independently comprises 1 or from 2 to 4 linked groups independently selected from —[C(R_(a))(R_(b))]_(n)—, —C(R_(a))═C(R_(b))—, —C(R_(a))═N—, —C(═O)—, —C(═NR_(a))—, —C(═S)—, —O—, —Si(R_(a))₂—, —S(═O)_(x)—, and —N(R_(a))—;

wherein:

x is 0, 1, or 2;

n is 1, 2, 3, or 4;

each R_(a) and R_(b) is, independently, H, a protecting group, hydroxyl, C₁-C₁₂ alkyl, substituted C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, substituted C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, substituted C₂-C₁₂ alkynyl, C₅-C₂₀ aryl, substituted C₅-C₂₀ aryl, heterocycle radical, substituted heterocycle radical, heteroaryl, substituted heteroaryl, C₅-C₇ alicyclic radical, substituted C₅-C₇ alicyclic radical, halogen, OJ₁, NJ₁J₂, SJ₁, N₃, COOJ₁, acyl (C(═O)—H), substituted acyl, CN, sulfonyl (S(═O)₂-J₁), or sulfoxyl (S(═O)-J₁); and

each J₁ and J₂ is, independently, H, C₁-C₁₂ alkyl, substituted C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, substituted C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, substituted C₂-C₁₂ alkynyl, C₅-C₂₀ aryl, substituted C₅-C₂₀ aryl, acyl (C(═O)—H), substituted acyl, a heterocycle radical, a substituted heterocycle radical, C₁-C₁₂ aminoalkyl, substituted C₁-C₁₂ aminoalkyl or a protecting group.

In certain embodiments, the bridge of a bicyclic sugar moiety is —[C(R_(a))(R_(b))]_(n)—, —[C(R_(a))(R_(b))]_(n)—O—, —C(R_(a)R_(b))—N(R)—O— or —C(R_(a)R_(b))—O—N(R)—. In certain embodiments, the bridge is 4′-CH₂-2′, 4′-(CH₂)₂-2′, 4′-(CH₂)₃-2′, 4′-CH₂—O-2′, 4′-(CH₂)₂—O-2′, 4′-CH₂—O—N(R)-2′ and 4′-CH₂—N(R)—O-2′- wherein each R is, independently, H, a protecting group or C₁-C₁₂ alkyl.

In certain embodiments, bicyclic nucleosides are further defined by isomeric configuration. For example, a nucleoside comprising a 4′-2′ methylene-oxy bridge, may be in the α-L configuration or in the β-D configuration. Previously, α-L-methyleneoxy (4′-CH₂—O-2′) BNA's have been incorporated into antisense oligonucleotides that showed antisense activity (Frieden et al., Nucleic Acids Research, 2003, 21, 6365-6372).

In certain embodiments, bicyclic nucleosides include, but are not limited to, (A) α-L-methyleneoxy (4′-CH₂—O-2′) BNA, (B) β-D-methyleneoxy (4′-CH₂—O-2′) BNA, (C) ethyleneoxy (4′-(CH₂)₂—O-2′) BNA, (D) aminooxy (4′-CH₂—O—N(R)-2′) BNA, (E) oxyamino (4′-CH₂—N(R)—O-2′) BNA, and (F) methyl(methyleneoxy) (4′-CH(CH₃)—O-2′) BNA, (G) methylene thio (4′-CH₂—S-2′) BNA, (H) methylene-amino (4′-CH₂—N(R)-2′) BNA, (I) methyl carbocyclic (4′-CH₂—CH(CH₃)-2′) BNA, and (J) propylene carbocyclic (4′-(CH₂)₃-2′) BNA as depicted below.

wherein Bx is the base moiety and R is independently H, a protecting group or C₁-C₁₂ alkyl.

In certain embodiments, bicyclic nucleosides are provided having Formula I:

wherein:

Bx is a heterocyclic base moiety;

-Q_(a)-Q_(b)-Q_(c)- is —CH₂—N(R_(c))—CH₂—, —C(═O)—N(R_(c))—CH₂—, —CH₂—O—N(R_(c))—, —CH₂—N(R_(c))—O— or —N(R_(c))—O—CH₂;

R_(c) is C₁-C₁₂ alkyl or an amino protecting group; and

T_(a) and T_(b) are each, independently H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety or a covalent attachment to a support medium.

In certain embodiments, bicyclic nucleosides are provided having Formula II:

wherein:

Bx is a heterocyclic base moiety;

T_(a) and T_(b) are each, independently H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety or a covalent attachment to a support medium;

Z_(a) is C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, substituted C₁-C₆ alkyl, substituted C₂-C₆ alkenyl, substituted C₂-C₆ alkynyl, acyl, substituted acyl, substituted amide, thiol or substituted thio.

In one embodiment, each of the substituted groups is, independently, mono or poly substituted with substituent groups independently selected from halogen, oxo, hydroxyl, OJ_(c), NJ_(c)J_(d), SJ_(c), N₃, OC(═X)J_(c), and NJ_(e)C(═X)NJ_(c)J_(d), wherein each J_(c), J_(d) and J_(e) is, independently, H, C₁-C₆ alkyl, or substituted C₁-C₆ alkyl and X is O or NJ_(c).

In certain embodiments, bicyclic nucleosides are provided having Formula III:

wherein:

Bx is a heterocyclic base moiety;

T_(a) and T_(b) are each, independently H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety or a covalent attachment to a support medium;

Z_(b) is C₁-C₆ alkyl, C₂-C₆ alkenyl, C₂-C₆ alkynyl, substituted C₁-C₆ alkyl, substituted C₂-C₆ alkenyl, substituted C₂-C₆ alkynyl or substituted acyl (C(═O)—).

In certain embodiments, bicyclic nucleosides are provided having Formula IV:

wherein:

Bx is a heterocyclic base moiety;

T_(a) and T_(b) are each, independently H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety or a covalent attachment to a support medium;

R_(d) is C₁-C₆ alkyl, substituted C₁-C₆ alkyl, C₂-C₆ alkenyl, substituted C₂-C₆ alkenyl, C₂-C₆ alkynyl or substituted C₂-C₆ alkynyl;

each q_(a), q_(b), q_(c) and q_(d) is, independently, H, halogen, C₁-C₆ alkyl, substituted C₁-C₆ alkyl, C₂-C₆ alkenyl, substituted C₂-C₆ alkenyl, C₂-C₆ alkynyl or substituted C₂-C₆ alkynyl, C₁-C₆ alkoxyl, substituted C₁-C₆ alkoxyl, acyl, substituted acyl, C₁-C₆ aminoalkyl or substituted C₁-C₆ aminoalkyl;

In certain embodiments, bicyclic nucleosides are provided having Formula V:

wherein:

Bx is a heterocyclic base moiety;

T_(a) and T_(b) are each, independently H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety or a covalent attachment to a support medium;

q_(a), q_(b), q_(e) and q_(f) are each, independently, hydrogen, halogen, C₁-C₁₂ alkyl, substituted C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, substituted C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, substituted C₂-C₁₂ alkynyl, C₁-C₁₂ alkoxy, substituted C₁-C₁₂ alkoxy, OJ_(j), SJ_(j), SOJ_(j), SO₂J_(j), NJ_(j)J_(k), N₃, CN, C(═O)OJ_(j), C(═O)NJ_(j)J_(k), C(═O)J_(j), O—C(═O)—NJ_(j)J_(k), N(H)C(═NH)NJ_(j)J_(k), N(H)C(═O)NJ_(j)J_(k) or N(H)C(═S)NJ_(j)J_(k);

or q_(e) and q_(f) together are ═C(q_(g))(q_(h));

q_(g) and q_(h) are each, independently, H, halogen, C₁-C₁₂ alkyl or substituted C₁-C₁₂ alkyl.

The synthesis and preparation of the methyleneoxy (4′-CH₂—O-2′) BNA monomers adenine, cytosine, guanine, 5-methyl-cytosine, thymine and uracil, along with their oligomerization, and nucleic acid recognition properties have been described (Koshkin et al., Tetrahedron, 1998, 54, 3607-3630). BNAs and preparation thereof are also described in WO 98/39352 and WO 99/14226.

Analogs of methyleneoxy (4′-CH₂—O-2′) BNA and 2′-thio-BNAs, have also been prepared (Kumar et al., Bioorg. Med. Chem. Lett., 1998, 8, 2219-2222). Preparation of locked nucleoside analogs comprising oligodeoxyribonucleotide duplexes as substrates for nucleic acid polymerases has also been described (Wengel et al., WO 99/14226). Furthermore, synthesis of 2′-amino-BNA, a novel comformationally restricted high-affinity oligonucleotide analog has been described in the art (Singh et al., J. Org. Chem., 1998, 63, 10035-10039). In addition, 2′-amino- and 2′-methylamino-BNA's have been prepared and the thermal stability of their duplexes with complementary RNA and DNA strands has been previously reported.

In certain embodiments, bicyclic nucleosides are provided having Formula VI:

wherein:

Bx is a heterocyclic base moiety;

T_(a) and T_(b) are each, independently H, a hydroxyl protecting group, a conjugate group, a reactive phosphorus group, a phosphorus moiety or a covalent attachment to a support medium;

each q_(i), q_(j), q_(k) and q_(l) is, independently, H, halogen, C₁-C₁₂ alkyl, substituted C₁-C₁₂ alkyl, C₂-C₁₂ alkenyl, substituted C₂-C₁₂ alkenyl, C₂-C₁₂ alkynyl, substituted C₂-C₁₂ alkynyl, C₁-C₁₂ alkoxyl, substituted C₁-C₁₂ alkoxyl, OJ_(j), SJ_(j), SOJ_(j), SO₂J_(j), NJ_(j)J_(k), N₃, CN, C(═O)OJ_(j), C(═O)NJ_(j)J_(k), C(═O)J_(j), O—C(═O)NJ_(j)J_(k), N(H)C(═NH)NJ_(j)J_(k), N(H)C(═O)NJ_(j)J_(k) or N(H)C(═S)NJ_(j)J_(k); and

q_(i) and q_(j) or q_(l) and q_(k) together are ═C(q_(g))(q_(h)), wherein q_(g) and q_(h) are each, independently, H, halogen, C₁-C₁₂ alkyl or substituted C₁-C₁₂ alkyl.

One carbocyclic bicyclic nucleoside having a 4′-(CH₂)₃-2′ bridge and the alkenyl analog bridge 4′-CH═CH—CH₂-2′ have been described (Freier et al., Nucleic Acids Research, 1997, 25(22), 4429-4443 and Albaek et al., J. Org. Chem., 2006, 71, 7731-7740). The synthesis and preparation of carbocyclic bicyclic nucleosides along with their oligomerization and biochemical studies have also been described (Srivastava et al., J. Am. Chem. Soc., 2007, 129(26), 8362-8379).

As used herein, “4′-2′ bicyclic nucleoside” or “4′ to 2′ bicyclic nucleoside” refers to a bicyclic nucleoside comprising a furanose ring comprising a bridge connecting two carbon atoms of the furanose ring connects the 2′ carbon atom and the 4′ carbon atom of the sugar ring.

As used herein, “monocylic nucleosides” refer to nucleosides comprising modified sugar moieties that are not bicyclic sugar moieties. In certain embodiments, the sugar moiety, or sugar moiety analogue, of a nucleoside may be modified or substituted at any position.

As used herein, “2′-modified sugar” means a furanosyl sugar modified at the 2′ position. In certain embodiments, such modifications include substituents selected from: a halide, including, but not limited to substituted and unsubstituted alkoxy, substituted and unsubstituted thioalkyl, substituted and unsubstituted amino alkyl, substituted and unsubstituted alkyl, substituted and unsubstituted allyl, and substituted and unsubstituted alkynyl. In certain embodiments, 2′ modifications are selected from substituents including, but not limited to: O[(CH₂)_(n)O]_(m)CH₃, O(CH₂)_(n)NH₂, O(CH₂)_(n)CH₃, O(CH₂)_(n)F, O(CH₂)_(n)ONH₂, OCH₂C(═O)N(H)CH₃, and O(CH₂)_(n)ON[(CH₂)_(n)CH₃]₂, where n and m are from 1 to about 10. Other 2′-substituent groups can also be selected from: C₁-C₁₂ alkyl, substituted alkyl, alkenyl, alkynyl, alkaryl, aralkyl, O-alkaryl or O-aralkyl, SH, SCH₃, OCN, Cl, Br, CN, F, CF₃, OCF₃, SOCH₃, SO₂CH₃, ONO₂, NO₂, N₃, NH₂, heterocycloalkyl, heterocycloalkaryl, aminoalkylamino, polyalkylamino, substituted silyl, an RNA cleaving group, a reporter group, an intercalator, a group for improving pharmacokinetic properties, or a group for improving the pharmacodynamic properties of an antisense compound, and other substituents having similar properties. In certain embodiments, modifed nucleosides comprise a 2′-MOE side chain (Baker et al., J. Biol. Chem., 1997, 272, 11944-12000). Such 2′-MOE substitution have been described as having improved binding affinity compared to unmodified nucleosides and to other modified nucleosides, such as 2′-O-methyl, O-propyl, and O-aminopropyl. Oligonucleotides having the 2′-MOE substituent also have been shown to be antisense inhibitors of gene expression with promising features for in vivo use (Martin, Helv. Chim. Acta., 1995, 78, 486-504; Altmann et al., Chimia, 1996, 50, 168-176; Altmann et al., Biochem. Soc. Trans., 1996, 24, 630-637; and Altmann et al., Nucleosides Nucleotides, 1997, 16, 917-926).

As used herein, a “modified tetrahydropyran nucleoside” or “modified THP nucleoside” means a nucleoside having a six-membered tetrahydropyran “sugar” substituted in for the pentofuranosyl residue in normal nucleosides (a sugar surrogate). Modified THP nucleosides include, but are not limited to, what is referred to in the art as hexitol nucleic acid (HNA), anitol nucleic acid (ANA), manitol nucleic acid (MNA) (see Leumann, Bioorg. Med. Chem., 2002, 10, 841-854), fluoro HNA (F-HNA) or those compounds having Formula VII:

wherein independently for each of said at least one tetrahydropyran nucleoside analog of Formula VII:

Bx is a heterocyclic base moiety;

T_(a) and T_(b) are each, independently, an internucleoside linking group linking the tetrahydropyran nucleoside analog to the antisense compound or one of T_(a) and T_(b) is an internucleoside linking group linking the tetrahydropyran nucleoside analog to the antisense compound and the other of T_(a) and T_(b) is H, a hydroxyl protecting group, a linked conjugate group or a 5′ or 3′-terminal group;

q₁, q₂, q₃, q₄, q₅, q₆ and q₇ are each independently, H, C₁-C₆ alkyl, substituted C₁-C₆ alkyl, C₂-C₆ alkenyl, substituted C₂-C₆ alkenyl, C₂-C₆ alkynyl or substituted C₂-C₆ alkynyl; and each of R₁ and R₂ is selected from hydrogen, hydroxyl, halogen, substituted or unsubstituted alkoxy, NJ1J₂, SJ₁, N₃, OC(═X)J₁, OC(═X)NJ₁J₂, NJ₃C(═X)NJ₁J₂ and CN, wherein X is O, S or NJ₁ and each J₁, J₂ and J₃ is, independently, H or C₁-C₆ alkyl.

In certain embodiments, the modified THP nucleosides of Formula VII are provided wherein q₁, q₂, q₃, q₄, q₅, q₆ and q₇ are each H. In certain embodiments, at least one of q₁, q₂, q₃, q₄, q₅, q₆ and q₇ is other than H. In certain embodiments, at least one of q₁, q₂, q₃, q₄, q₅, q₆ and q₇ is methyl. In certain embodiments, THP nucleosides of Formula VII are provided wherein one of R₁ and R₂ is fluoro. In certain embodiments, R₁ is fluoro and R₂ is H; R₁ is methoxy and R₂ is H, and R₁ is methoxyethoxy and R₂ is H.

As used herein, “2′-modified” or “2′-substituted” refers to a nucleoside comprising a sugar comprising a substituent at the 2′ position other than H or OH. 2′-modified nucleosides, include, but are not limited to, bicyclic nucleosides wherein the bridge connecting two carbon atoms of the sugar ring connects the 2′ carbon and another carbon of the sugar ring; and nucleosides with non-bridging 2′substituents, such as allyl, amino, azido, thio, O-allyl, O—C₁-C₁₀ alkyl, —OCF₃, O—(CH₂)₂—O—CH₃, 2′-O(CH₂)₂SCH₃, O—(CH₂)₂—O—N(R_(m))(R_(n)), or O—CH₂—C(═O)—N(R_(m))(R_(n)), where each R_(m) and R_(n) is, independently, H or substituted or unsubstituted C₁-C₁₀ alkyl. 2′-modifed nucleosides may further comprise other modifications, for example at other positions of the sugar and/or at the nucleobase.

As used herein, “2′-F” refers to a nucleoside comprising a sugar comprising a fluoro group at the 2′ position.

As used herein, “2′-OMe” or “2′-OCH₃” or “2′-O-methyl” each refers to a nucleoside comprising a sugar comprising an —OCH₃ group at the 2′ position of the sugar ring.

As used herein, “MOE” or “2′-MOE” or “2′-OCH₂CH₂OCH₃” or “2′-O-methoxyethyl” each refers to a nucleoside comprising a sugar comprising a —OCH₂CH₂OCH₃ group at the 2′ position of the sugar ring.

As used herein, “oligonucleotide” refers to a compound comprising a plurality of linked nucleosides. In certain embodiments, one or more of the plurality of nucleosides is modified. In certain embodiments, an oligonucleotide comprises one or more ribonucleosides (RNA) and/or deoxyribonucleosides (DNA).

Many other bicyclo and tricyclo sugar surrogate ring systems are also known in the art that can be used to modify nucleosides for incorporation into antisense compounds (see for example review article: Leumann, Bioorg. Med. Chem., 2002, 10, 841-854). Such ring systems can undergo various additional substitutions to enhance activity.

Methods for the preparations of modified sugars are well known to those skilled in the art.

In nucleotides having modified sugar moieties, the nucleobase moieties (natural, modified or a combination thereof) are maintained for hybridization with an appropriate nucleic acid target.

In certain embodiments, antisense compounds comprise one or more nucleosides having modified sugar moieties. In certain embodiments, the modified sugar moiety is 2′-MOE. In certain embodiments, the 2′-MOE modified nucleosides are arranged in a gapmer motif. In certain embodiments, the modified sugar moiety is a bicyclic nucleoside having a (4′-CH(CH₃)—O-2′) bridging group. In certain embodiments, the (4′-CH(CH₃)—O-2′) modified nucleosides are arranged throughout the wings of a gapmer motif.

Modified Nucleobases

Nucleobase (or base) modifications or substitutions are structurally distinguishable from, yet functionally interchangeable with, naturally occurring or synthetic unmodified nucleobases. Both natural and modified nucleobases are capable of participating in hydrogen bonding. Such nucleobase modifications may impart nuclease stability, binding affinity or some other beneficial biological property to antisense compounds. Modified nucleobases include synthetic and natural nucleobases such as, for example, 5-methylcytosine (5-me-C). Certain nucleobase substitutions, including 5-methylcytosine substitutions, are particularly useful for increasing the binding affinity of an antisense compound for a target nucleic acid. For example, 5-methylcytosine substitutions have been shown to increase nucleic acid duplex stability by 0.6-1.2° C. (Sanghvi, Y. S., Crooke, S. T. and Lebleu, B., eds., Antisense Research and Applications, CRC Press, Boca Raton, 1993, pp. 276-278).

Additional unmodified nucleobases include 5-hydroxymethyl cytosine, xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and other alkyl derivatives of adenine and guanine, 2-propyl and other alkyl derivatives of adenine and guanine, 2-thiouracil, 2-thiothymine and 2-thiocytosine, 5-halouracil and cytosine, 5-propynyl (—C≡C—CH₃) uracil and cytosine and other alkynyl derivatives of pyrimidine bases, 6-azo uracil, cytosine and thymine, 5-uracil (pseudouracil), 4-thiouracil, 8-halo, 8-amino, 8-thiol, 8-thioalkyl, 8-hydroxyl and other 8-substituted adenines and guanines, 5-halo particularly 5-bromo, 5-trifluoromethyl and other 5-substituted uracils and cytosines, 7-methylguanine and 7-methyladenine, 2-F-adenine, 2-amino-adenine, 8-azaguanine and 8-azaadenine, 7-deazaguanine and 7-deazaadenine and 3-deazaguanine and 3-deazaadenine.

Heterocyclic base moieties may also include those in which the purine or pyrimidine base is replaced with other heterocycles, for example 7-deaza-adenine, 7-deazaguanosine, 2-aminopyridine and 2-pyridone. Nucleobases that are particularly useful for increasing the binding affinity of antisense compounds include 5-substituted pyrimidines, 6-azapyrimidines and N-2, N-6 and O-6 substituted purines, including 2 aminopropyladenine, 5-propynyluracil and 5-propynylcytosine.

In certain embodiments, antisense compounds targeted to a TMPRSS6 nucleic acid comprise one or more modified nucleobases. In certain embodiments, gap-widened antisense oligonucleotides targeted to a TMPRSS6 nucleic acid comprise one or more modified nucleobases. In certain embodiments, the modified nucleobase is 5-methylcytosine. In certain embodiments, each cytosine is a 5-methylcytosine.

Compositions and Methods for Formulating Pharmaceutical Compositions

Antisense oligonucleotides may be admixed with pharmaceutically acceptable active or inert substance for the preparation of pharmaceutical compositions or formulations. Compositions and methods for the formulation of pharmaceutical compositions are dependent upon a number of criteria, including, but not limited to, route of administration, extent of disease, or dose to be administered.

Antisense compound targeted to a TMPRSS6 nucleic acid can be utilized in pharmaceutical compositions by combining the antisense compound with a suitable pharmaceutically acceptable diluent or carrier. A pharmaceutically acceptable diluent includes phosphate-buffered saline (PBS). PBS is a diluent suitable for use in compositions to be delivered parenterally. Accordingly, in one embodiment, employed in the methods described herein is a pharmaceutical composition comprising an antisense compound targeted to a TMPRSS6 nucleic acid and a pharmaceutically acceptable diluent. In certain embodiments, the pharmaceutically acceptable diluent is PBS. In certain embodiments, the antisense compound is an antisense oligonucleotide.

Pharmaceutical compositions comprising antisense compounds encompass any pharmaceutically acceptable salts, esters, or salts of such esters, or any other oligonucleotide which, upon administration to an animal, including a human, is capable of providing (directly or indirectly) the biologically active metabolite or residue thereof. Accordingly, for example, the disclosure is also drawn to pharmaceutically acceptable salts of antisense compounds, prodrugs, pharmaceutically acceptable salts of such prodrugs, and other bioequivalents. Suitable pharmaceutically acceptable salts include, but are not limited to, sodium and potassium salts.

Pharmaceutically acceptable salts of the compounds described herein may be prepared by methods well-known in the art. For a review of pharmaceutically acceptable salts, see Stahl and Wermuth, Handbook of Pharmaceutical Salts: Properties, Selection and Use (Wiley-VCH, Weinheim, Germany, 2002). Sodium salts of antisense oligonucleotides are useful and are well accepted for therapeutic administration to humans. Accordingly, in one embodiment the compounds described herein are in the form of a sodium salt.

A prodrug can include the incorporation of additional nucleosides at one or both ends of an antisense compound which are cleaved by endogenous nucleases within the body, to form the active antisense compound.

Dosing

In certain embodiments, pharmaceutical compositions are administered according to a dosing regimen (e.g., dose, dose frequency, and duration) wherein the dosing regimen can be selected to achieve a desired effect. The desired effect can be, for example, reduction of TMPRSS6 or the prevention, reduction, amelioration or slowing the progression of a disease, disorder or condition associated with TMPRSS6.

In certain embodiments, the variables of the dosing regimen are adjusted to result in a desired concentration of pharmaceutical composition in a subject. “Concentration of pharmaceutical composition” as used with regard to dose regimen can refer to the compound, oligonucleotide, or active ingredient of the pharmaceutical composition. For example, in certain embodiments, dose and dose frequency are adjusted to provide a tissue concentration or plasma concentration of a pharmaceutical composition at an amount sufficient to achieve a desired effect.

Dosing is dependent on severity and responsiveness of the disease state to be treated, with the course of treatment lasting from several days to several months, or until a cure is effected or a diminution of the disease state is achieved. Dosing is also dependent on drug potency and metabolism. In certain embodiments, dosage is from 0.01 μg to 100 mg per kg of body weight, or within a range of 0.001 mg to 1000 mg dosing, and may be given once or more daily, weekly, monthly or yearly, or even once every 2 to 20 years. Following successful treatment, it may be desirable to have the patient undergo maintenance therapy to prevent the recurrence of the disease state, wherein the oligonucleotide is administered in maintenance doses, ranging from 0.01 μg to 100 mg per kg of body weight, once or more daily, to once every 20 years or ranging from 0.001 mg to 1000 mg dosing.

Administration

The compounds or pharmaceutical compositions of the present invention can be administered in a number of ways depending upon whether local or systemic treatment is desired and upon the area to be treated. Administration can be oral, inhaled or parenteral.

In certain embodiments, the compounds and compositions as described herein are administered parenterally. Parenteral administration includes intravenous, intra-arterial, subcutaneous, intraperitoneal or intramuscular injection or infusion; or intracranial, e.g., intrathecal or intraventricular, administration.

In certain embodiments, parenteral administration is by infusion. Infusion can be chronic or continuous or short or intermittent. In certain embodiments, infused pharmaceutical agents are delivered with a pump.

In certain embodiments, parenteral administration is by injection. The injection can be delivered with a syringe or a pump. In certain embodiments, the injection is a bolus injection. In certain embodiments, the injection is administered directly to a tissue or organ.

In certain embodiments, formulations for parenteral, intrathecal or intraventricular administration can include sterile aqueous solutions which can also contain buffers, diluents and other suitable additives such as, but not limited to, penetration enhancers, carrier compounds and other pharmaceutically acceptable carriers or excipients.

In certain embodiments, formulations for oral administration of the compounds or compositions can include, but is not limited to, pharmaceutical carriers, excipients, powders or granules, microparticulates, nanoparticulates, suspensions or solutions in water or non-aqueous media, capsules, gel capsules, sachets, tablets or minitablets. Thickeners, flavoring agents, diluents, emulsifiers, dispersing aids or binders can be desirable. In certain embodiments, oral formulations are those in which compounds provided herein are administered in conjunction with one or more penetration enhancers, surfactants and chelators.

In certain embodiments, administration includes pulmonary administration. In certain embodiments, pulmonary administration comprises delivery of aerosolized oligonucleotide to the lung of a subject by inhalation. Following inhalation by a subject of aerosolized oligonucleotide, oligonucleotide distributes to cells of both normal and inflamed lung tissue, including alveolar macrophages, eosinophils, epithelium, blood vessel endothelium, and bronchiolar epithelium. A suitable device for the delivery of a pharmaceutical composition comprising a modified oligonucleotide includes, but is not limited to, a standard nebulizer device. Additional suitable devices include dry powder inhalers or metered dose inhalers.

In certain embodiments, pharmaceutical compositions are administered to achieve local rather than systemic exposures. For example, pulmonary administration delivers a pharmaceutical composition to the lung, with minimal systemic exposure.

Additional suitable administration routes include, but are not limited to, rectal, transmucosal, intestinal, enteral, topical, suppository, intrathecal, intraventricular, intraperitoneal, intranasal, intraocular, intramuscular, intramedullary, and intratumoral.

Conjugated Antisense Compounds

In certain embodiments, the compounds of the invention can be covalently linked to one or more moieties or conjugates which enhance the activity, cellular distribution or cellular uptake of the resulting antisense oligonucleotides. Typical conjugate groups include cholesterol moieties and lipid moieties. Additional conjugate groups include carbohydrates, phospholipids, biotin, phenazine, folate, phenanthridine, anthraquinone, acridine, fluoresceins, rhodamines, coumarins, and dyes.

In certain embodiments, antisense compounds can also be modified to have one or more stabilizing groups that are generally attached to one or both termini of antisense compounds to enhance properties such as, for example, nuclease stability. Included in stabilizing groups are cap structures. These terminal modifications protect the antisense compound having terminal nucleic acid from exonuclease degradation, and can help in delivery and/or localization within a cell. The cap can be present at the 5′-terminus (5′-cap), or at the 3′ terminus (3′-cap), or can be present on both termini. Cap structures are well known in the art and include, for example, inverted deoxy abasic caps. Further 3′ and 5′-stabilizing groups that can be used to cap one or both ends of an antisense compound to impart nuclease stability include those disclosed in WO 03/004602 published on Jan. 16, 2003.

Cell Culture and Antisense Compounds Treatment

The effects of antisense compounds on the level, activity or expression of TMPRSS6 nucleic acids can be tested in vitro in a variety of cell types. Cell types used for such analyses are available from commercial vendors (e.g. American Type Culture Collection, Manassas, Va.; Zen-Bio, Inc., Research Triangle Park, N.C.; Clonetics Corporation, Walkersville, Md.) and cells are cultured according to the vendor's instructions using commercially available reagents (e.g. Invitrogen Life Technologies, Carlsbad, Calif.). Illustrative cell types include, but are not limited to, HepG2 cells, Hep3B cells, Huh7 (hepatocellular carcinoma) cells, primary hepatocytes, A549 cells, GM04281 fibroblasts and LLC-MK2 cells.

In Vitro Testing of Antisense Oligonucleotides

Described herein are methods for treatment of cells with antisense oligonucleotides, which can be modified appropriately for treatment with other antisense compounds.

In general, cells are treated with antisense oligonucleotides when the cells reach approximately 60-80% confluence in culture.

One reagent commonly used to introduce antisense oligonucleotides into cultured cells includes the cationic lipid transfection reagent LIPOFECTIN® (Invitrogen, Carlsbad, Calif.). Antisense oligonucleotides are mixed with LIPOFECTIN® in OPTI-MEM® 1 (Invitrogen, Carlsbad, Calif.) to achieve the desired final concentration of antisense oligonucleotide and a LIPOFECTIN® concentration that typically ranges 2 to 12 ug/mL per 100 nM antisense oligonucleotide.

Another reagent used to introduce antisense oligonucleotides into cultured cells includes LIPOFECTAMINE 2000® (Invitrogen, Carlsbad, Calif.). Antisense oligonucleotide is mixed with LIPOFECTAMINE 2000® in OPTI-MEM® 1 reduced serum medium (Invitrogen, Carlsbad, Calif.) to achieve the desired concentration of antisense oligonucleotide and a LIPOFECTAMINE® concentration that typically ranges 2 to 12 ug/mL per 100 nM antisense oligonucleotide.

Another reagent used to introduce antisense oligonucleotides into cultured cells includes Cytofectin® (Invitrogen, Carlsbad, Calif.). Antisense oligonucleotide is mixed with Cytofectin® in OPTI-MEM® 1 reduced serum medium (Invitrogen, Carlsbad, Calif.) to achieve the desired concentration of antisense oligonucleotide and a Cytofectin® concentration that typically ranges 2 to 12 ug/mL per 100 nM antisense oligonucleotide.

Another reagent used to introduce antisense oligonucleotides into cultured cells includes Oligofectamine™ (Invitrogen Life Technologies, Carlsbad, Calif.). Antisense oligonucleotide is mixed with Oligofectamine™ in Opti-MEM™-1 reduced serum medium (Invitrogen Life Technologies, Carlsbad, Calif.) to achieve the desired concentration of oligonucleotide with an Oligofectamine™ to oligonucleotide ratio of approximately 0.2 to 0.8 μL per 100 nM.

Another reagent used to introduce antisense oligonucleotides into cultured cells includes FuGENE 6 (Roche Diagnostics Corp., Indianapolis, Ind.). Antisense oligomeric compound was mixed with FuGENE 6 in 1 mL of serum-free RPMI to achieve the desired concentration of oligonucleotide with a FuGENE 6 to oligomeric compound ratio of 1 to 4 μL of FuGENE 6 per 100 nM.

Another technique used to introduce antisense oligonucleotides into cultured cells includes electroporation (Sambrook and Russell in Molecular Cloning. A Laboratory Manual. Third Edition. Cold Spring Harbor laboratory Press, Cold Spring Harbor, N.Y. 2001).

Cells are treated with antisense oligonucleotides by routine methods. Cells are typically harvested 16-24 hours after antisense oligonucleotide treatment, at which time RNA or protein levels of target nucleic acids are measured by methods known in the art and described herein (Sambrook and Russell in Molecular Cloning. A Laboratory Manual. Third Edition. Cold Spring Harbor laboratory Press, Cold Spring Harbor, N.Y. 2001). In general, when treatments are performed in multiple replicates, the data are presented as the average of the replicate treatments.

The concentration of antisense oligonucleotide used varies from cell line to cell line. Methods to determine the optimal antisense oligonucleotide concentration for a particular cell line are well known in the art (Sambrook and Russell in Molecular Cloning. A Laboratory Manual. Third Edition. Cold Spring Harbor laboratory Press, Cold Spring Harbor, N.Y. 2001). Antisense oligonucleotides are typically used at concentrations ranging from 1 nM to 300 nM when transfected with LIPOFECTAMINE2000®, Lipofectin or Cytofectin. Antisense oligonucleotides are used at higher concentrations ranging from 625 to 20,000 nM when transfected using electroporation.

RNA Isolation

RNA analysis can be performed on total cellular RNA or poly(A)+ mRNA. Methods of RNA isolation are well known in the art (Sambrook and Russell, Molecular Cloning: A Laboratory Manual, 3^(rd) Ed., 2001). RNA is prepared using methods well known in the art, for example, using the TRIZOL® Reagent (Invitrogen, Carlsbad, Calif.) according to the manufacturer's recommended protocols.

Analysis of Inhibition of Target Levels or Expression

Inhibition of levels or expression of a TMPRSS6 nucleic acid can be assayed in a variety of ways known in the art (Sambrook and Russell, Molecular Cloning: A Laboratory Manual, 3^(rd) Ed., 2001). For example, target nucleic acid levels can be quantitated by, e.g., Northern blot analysis, competitive polymerase chain reaction (PCR), or quantitaive real-time PCR. RNA analysis can be performed on total cellular RNA or poly(A)+ mRNA. Methods of RNA isolation are well known in the art. Northern blot analysis is also routine in the art. Quantitative real-time PCR can be conveniently accomplished using the commercially available ABI PRISM® 7600, 7700, or 7900 Sequence Detection System, available from PE-Applied Biosystems, Foster City, Calif. and used according to manufacturer's instructions.

Quantitative Real-Time PCR Analysis of Target RNA Levels

Quantitation of target RNA levels may be accomplished by quantitative real-time PCR using the ABI PRISM® 7600, 7700, or 7900 Sequence Detection System (PE-Applied Biosystems, Foster City, Calif.) according to manufacturer's instructions. Methods of quantitative real-time PCR are well known in the art.

Prior to real-time PCR, the isolated RNA is subjected to a reverse transcriptase (RT) reaction, which produces complementary DNA (cDNA) that is then used as the substrate for the real-time PCR amplification. The RT and real-time PCR reactions are performed sequentially in the same sample well. RT and real-time PCR reagents are obtained from Invitrogen (Carlsbad, Calif.). RT, real-time-PCR reactions are carried out by methods well known to those skilled in the art.

Gene (or RNA) target quantities obtained by real time PCR are normalized using either the expression level of a gene whose expression is constant, such as cyclophilin A, or by quantifying total RNA using RIBOGREEN® (Invitrogen, Inc. Carlsbad, Calif.). Cyclophilin A expression is quantified by real time PCR, by being run simultaneously with the target, multiplexing, or separately. Total RNA is quantified using RIBOGREEN® RNA quantification reagent (Invitrogen, Inc. Eugene, Oreg.). Methods of RNA quantification by RIBOGREEN® are taught in Jones, L. J., et al, (Analytical Biochemistry, 1998, 265, 368-374). A CYTOFLUOR® 4000 instrument (PE Applied Biosystems) is used to measure RIBOGREEN® fluorescence.

Probes and primers are designed to hybridize to a TMPRSS6 nucleic acid. Methods for designing real-time PCR probes and primers are well known in the art, and may include the use of software such as PRIMER EXPRESS® Software (Applied Biosystems, Foster City, Calif.).

Analysis of Protein Levels

Antisense inhibition of TMPRSS6 nucleic acids can be assessed by measuring TMPRSS6 protein levels. Protein levels of TMPRSS6 can be evaluated or quantitated in a variety of ways well known in the art, such as immunoprecipitation, Western blot analysis (immunoblotting), enzyme-linked immunosorbent assay (ELISA), quantitative protein assays, protein activity assays (for example, caspase activity assays), immunohistochemistry, immunocytochemistry or fluorescence-activated cell sorting (FACS) (Sambrook and Russell, Molecular Cloning: A Laboratory Manual, 3^(rd) Ed., 2001). Antibodies directed to a target can be identified and obtained from a variety of sources, such as the MSRS catalog of antibodies (Aerie Corporation, Birmingham, Mich.), or can be prepared via conventional monoclonal or polyclonal antibody generation methods well known in the art.

In Vivo Testing of Antisense Compounds

Antisense compounds, for example, antisense oligonucleotides, are tested in animals to assess their ability to inhibit expression of TMPRSS6 and produce phenotypic changes, such as, reduced accumulation of iron in the body. Testing can be performed in normal animals, or in experimental disease models. Testing may be performed in normal animals, or in experimental disease models. For administration to animals, antisense oligonucleotides are formulated in a pharmaceutically acceptable diluent, such as phosphate-buffered saline. Administration includes parenteral routes of administration, such as intraperitoneal, intravenous, and subcutaneous. Calculation of antisense oligonucleotide dosage and dosing frequency depends upon factors such as route of administration and animal body weight. In one embodiment, following a period of treatment with antisense oligonucleotides, RNA is isolated from liver tissue and changes in TMPRSS6 nucleic acid expression are measured. Changes in TMPRSS6 protein levels can also be measured. Changes in TMPRSS6 expression can be measured by determining the level of hepcidin expression, plasma levels of iron and percentage saturation of transferrin present in the animal.

Certain Indications

In certain embodiments, provided herein are methods of treating an individual comprising administering one or more pharmaceutical compositions of the present invention. In certain embodiments, the individual has or is at risk for an iron accumulation disease, disorder or condition. In certain embodiments, the individual is at risk for an iron accumulation disease, disorder or condition as described, supra. In certain embodiments the invention provides methods for prophylactically reducing TMPRSS6 expression in an individual. Certain embodiments include treating an individual in need thereof by administering to an individual a therapeutically effective amount of an antisense compound targeted to a TMPRSS6 nucleic acid.

In certain embodiments, administration of a therapeutically effective amount of an antisense compound targeted to a TMPRSS6 nucleic acid is accompanied by monitoring of TMPRSS6 levels in an individual, to determine an individual's response to administration of the antisense compound. In certain embodiments, administration of a therapeutically effective amount of an antisense compound targeted to a TMPRSS6 nucleic acid is accompanied by monitoring the levels of hepcidin in an individual. In certain embodiments, administration of a therapeutically effective amount of an antisense compound targeted to a TMPRSS6 nucleic acid is accompanied by monitoring the levels of iron in an individual. In certain embodiments, administration of a therapeutically effective amount of an antisense compound targeted to a TMPRSS6 nucleic acid is accompanied by evaluating the percentage saturation of transferrin in an individual. An individual's response to administration of the antisense compound is used by a physician to determine the amount and duration of therapeutic intervention.

In certain embodiments, pharmaceutical compositions comprising an antisense compound targeted to TMPRSS6 are used for the preparation of a medicament for treating a patient suffering or susceptible to an iron accumulation disease, disorder or condition.

In certain embodiments, the methods described herein include administering a compound comprising a modified oligonucleotide having an 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 contiguous nucleobase portion complementary to a TMPRSS6 nucleic acid.

Certain Combination Therapies

In certain embodiments, a first agent comprising a modified oligonucleotide provided herein is co-administered with one or more secondary agents. In certain embodiments, such second agents are designed to treat the same iron accumulation disease, disorder or condition as the first agent described herein. In certain embodiments, such second agents are designed to treat a different disease, disorder, or condition as the first agent described herein. In certain embodiments, such second agents are designed to treat an undesired side effect of one or more pharmaceutical compositions as described herein. In certain embodiments, such first agents are designed to treat an undesired side effect of a second agent. In certain embodiments, second agents are co-administered with the first agent to treat an undesired effect of the first agent. In certain embodiments, second agents are co-administered with the first agent to produce a combinational effect. In certain embodiments, second agents are co-administered with the first agent to produce a synergistic effect. In certain embodiments, the co-administration of the first and second agents permits use of lower dosages than would be required to achieve a therapeutic or prophylactic effect if the agents were administered as independent therapy.

In certain embodiments, a first agent and one or more second agents are administered at the same time. In certain embodiments, the first agent and one or more second agents are administered at different times. In certain embodiments, the first agent and one or more second agents are prepared together in a single pharmaceutical formulation. In certain embodiments, the first agent and one or more second agents are prepared separately.

In certain embodiments, second agents include, but are not limited to, nucleic acid compounds. Such nucleic acid compounds can include a siRNA, a ribozyme or an antisense compound targeting TMPRSS6 or another target.

In certain embodiments, second agents include, but are not limited to, non-antisense compounds such as iron chelators, transferrin, bone morphogenetic proteins 6 (BMP6), hepcidin agonists, stem cells or fetal hemoglobin (HbF)-raising agents. In further embodiments, iron chelators are selected from, but not limited to, FBS0701 (FerroKin), Exjade, Desferal, and Deferiprone. In certain embodiments, HBF-raising agents include 5-hydroxyl urea, short chain fatty acid (SCFA) derivatives (e.g., HQK1001), DNA methyltransferase inhibitors (e.g., decitabine) or histone deacetylase (HDAC) inhibitors (e.g., Zolina, Panobinostat). In certain embodiments, the second agent is administered prior to administration of the first agent. In certain embodiments, the second agent is administered following administration of the first agent. In certain embodiments the second agent is administered at the same time as the first agent. In certain embodiments the dose of a co-administered second agent is the same as the dose that would be administered if the second agent was administered alone. In certain embodiments the dose of a co-administered second agent is lower than the dose that would be administered if the second agent was administered alone. In certain embodiments the dose of a co-administered second agent is greater than the dose that would be administered if the second agent was administered alone. In certain embodiments, the first agent is administered at the same time as phlebotomy therapy. In certain embodiments, the first agent is administered prior to phlebotomy therapy. In certain embodiments, the first agent is administered following phlebotomy therapy. In certain embodiments, the frequency of phlebotomy is decreased. In certain embodiments, the length of time required for phlebotomy is decreased.

Advantages of the Invention

Provided herein, for the first time, are methods and compositions for the modulation of TMPRSS6 that can treat, prevent and/or ameliorate an iron accumulation disease. In a particular embodiment, provided are TMPRSS6 inhibitors such as antisense oligonucleotides (oligonucleotides targeting a nucleic acid encoding TMPRSS6 protein) to ameliorate an iron accumulation disorder such as hemochromatosis, polycythemia or thalassemia.

Targeting TMPRSS6 with TMPRSS6 specific inhibitors as described herein has several positive effects including, but not limited to: (a) increasing hepcidin levels, (b) preventing excessive iron absorption and iron overload, (c) increasing serum transferrin concentrations, which will further decrease transferrin saturation and hemichrome formation, (d) safely storing excess iron in macrophages and (e) decreasing transferrin saturation, leading to a decreased iron supply for erythropoiesis.

EXAMPLES

Non-Limiting Disclosure and Incorporation by Reference

While certain compounds, compositions and methods described herein have been described with specificity in accordance with certain embodiments, the following examples serve only to illustrate the compounds described herein and are not intended to limit the same. Each of the references recited in the present application is incorporated herein by reference in its entirety.

Example 1: In Vivo Antisense Inhibition of Murine Type II Transmembrane Serine Protease 6 (TMPRSS6)

Several antisense oligonucleotides were designed targeting murine TMPRSS6 mRNA (GENBANK Accession No. NM_027902.2, incorporated herein as SEQ ID NO: 1). The target start sites and sequences of each oligonucleotide are presented in Table 1. The chimeric antisense oligonucleotides in Table 1 were designed as 5-10-5 MOE gapmers. The gapmers are 20 nucleosides in length, wherein the central gap segment is comprised of ten 2′-deoxynucleosides and is flanked on both sides (in the 5′ and 3′ directions) by wings comprising five nucleosides each. Each nucleoside in the 5′ wing segment and each nucleoside in the 3′ wing segment has a 2′-MOE modification. The internucleoside linkages throughout each gapmer are phosphorothioate (P═S) linkages. All cytosine residues throughout each gapmer are 5-methylcytosines.

TABLE 1 Gapmers targeting murine TMPRSS6 Target ISIS Start SEQ No Sequence Site ID NO 537402 AGGCCTTCCGGGTCCACCTC  795  8 537450 TTTCTTTCCTACAGAGACCC 2933  9 537451 AGCCTTGATAGAGGCACCTT 3001 10 537452 GCTTAGAGTACAGCCCACTT 3044 11 537480 TCACCAGGCCTTCCGGGTCC  800 12 537524 AGGCATCCTAACCACCAGCT 2789 13 Treatment

Groups of four C57BL/6 mice each were injected with 25 mg/kg of ISIS 537402, ISIS 537450, ISIS 537451, ISIS 537452, ISIS 537480, or ISIS 537524 twice weekly for 4 weeks. A group of four mice each were injected with 25 mg/kg of control oligonucleotide, ISIS 141923 (CCTTCCCTGAAGGTTCCTCC, designated herein as SEQ ID NO: 14; a 5-10-5 MOE gapmer with no known murine target), twice weekly for 4 weeks. A control group of mice was injected with phosphate buffered saline (PBS) twice weekly for 4 weeks. Mice were sacrificed two days after the final dose.

RNA Analysis

RNA was extracted from liver tissue for real-time PCR analysis of TMPRSS6, using primer probe set RTS3481 (forward sequence ATTCCACGCTGGGCTGTTAT, designated herein as SEQ ID NO: 15; reverse sequence CTGGTCAGGCCCCTTCAA, designated herein as SEQ ID NO: 16; probe sequence TGAACCCAGGCCAGGTCCTCCC, designated herein as SEQ ID NO: 17). RT-PCR analysis of hepcidin was also conducted, using primer probe set RTS1777 (forward sequence TGCAGAAGAGAAGGAAGAGAGACA, designated herein as SEQ ID NO: 18; reverse sequence CACACTGGGAATTGTTACAGCATT, designated herein as SEQ ID NO: 19; probe sequence CAACTTCCCCATCTGCATCTTCTGCTGT, designated herein as SEQ ID NO: 20). The mRNA levels were normalized using RIBOGREEN®. As shown in Table 2, most of the antisense oligonucleotides achieved reduction of murine TMPRSS6 over the PBS control. Results are presented as percent inhibition of TMPRSS6, relative to control. As shown in Table 3, most of the antisense oligonucleotides achieved increase in murine hepcidin levels compared to the PBS control. Results are presented as percent change of hepcidin levels, relative to the control.

TABLE 2 Percent inhibition of murine TMPRSS6 mRNA levels in C57BL/6 mice ISIS % inhibition NO of TMPRSS6 537402 65 537450 80 537451 39 537452 86 537480 60 537524 90 141923 0

TABLE 3 Percent increase in murine hepcidin mRNA levels in C57BL/6 mice ISIS NO % hepcidin 537402 +28 537450 +113 537451 −7 537452 +201 537480 +13 537524 +181 141923 −38 Effect on Iron Levels

Serum iron levels were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Siek, G. et al., Clin. Chem. 48: 161-166, 2002). The results are presented in Table 4, expressed as μg/dL. The results indicate that several of the ISIS oligonucleotides reduced iron levels.

TABLE 4 Iron levels (μg/dL) in C57BL/6 mice Iron (μg/dL) PBS 161 ISIS 537402 148 ISIS 537450 94 ISIS 537451 161 ISIS 537452 82 ISIS 537480 135 ISIS 537524 104 ISIS 141923 144 Body and Organ Weights

The effect of antisense inhibition of TMPRSS6 on the overall health of the animals, as demonstrated by changes in body and organ weights, was assessed. As shown in Table 5, there was no significant change in the body weights of the mice treated with antisense oligonucleotide, compared to that of the PBS control. Similarly, as shown in Table 6, there was negligible change in organ weights of the mice treated with antisense oligonucleotide, compared to that of the PBS control.

TABLE 5 Body weights (g) of C57BL/6 mice Body weight (g) PBS 24.6 ISIS 537402 26.1 ISIS 537450 22.7 ISIS 537451 26.0 ISIS 537452 25.2 ISIS 537480 26.4 ISIS 537524 27.2 ISIS 141923 26.8

TABLE 6 Organ weights (g) of C57BL/6 mice Liver Kidney Spleen PBS 1.4 0.08 0.34 ISIS 537402 1.6 0.09 0.31 ISIS 537450 1.5 0.09 0.33 ISIS 537451 1.6 0.08 0.33 ISIS 537452 1.6 0.09 0.34 ISIS 537480 1.7 0.08 0.34 ISIS 537524 1.6 0.11 0.35 ISIS 141923 1.6 0.09 0.31 Liver Function

To evaluate the effect of ISIS oligonucleotides on hepatic function, plasma concentrations of transaminases were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Nyblom, H. et al., Alcohol & Alcoholism 39: 336-339, 2004; Tietz N W (Ed): Clinical Guide to Laboratory Tests, 3rd ed. W. B. Saunders, Philadelphia, Pa., 1995). Plasma concentrations of ALT (alanine transaminase) and AST (aspartate transaminase) were measured and the results are presented in Table 7 expressed in IU/L. Several of the ISIS oligonucleotides were considered tolerable in the mice, as demonstrated by their liver transaminase profile.

TABLE 7 ALT and AST levels (IU/L) of C57BL/6 mice ALT AST PBS 40 59 ISIS 537402 42 63 ISIS 537450 49 77 ISIS 537451 54 67 ISIS 537452 38 67 ISIS 537480 35 58 ISIS 537524 219 180 ISIS 141923 60 83 Kidney Function

To evaluate the effect of ISIS oligonucleotides on renal function, plasma concentrations of BUN were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Nyblom, H. et al., Alcohol & Alcoholism 39: 336-339, 2004; Tietz N W (Ed): Clinical Guide to Laboratory Tests, 3rd ed. W. B. Saunders, Philadelphia, Pa., 1995). The results are presented in Table 8 expressed in mg/dL. Several of the ISIS oligonucleotides were considered tolerable in the mice, as demonstrated by their plasma BUN profile.

TABLE 8 BUN levels (mg/dL) of C57BL/6 mice BUN PBS 41 ISIS 537402 43 ISIS 537450 42 ISIS 537451 47 ISIS 537452 37 ISIS 537480 34 ISIS 537524 40 ISIS 141923 35

Example 2: Effect of Dose-Dependent Antisense Inhibition of Murine TMPRSS6

The effect of treatment with several dose concentrations of ISIS 537450 and ISIS 537452 was assessed in C57BL/6 wildtype mice.

Treatment

Three groups of four C57BL/6 mice each were injected with 25 mg/kg, 50 mg/kg, or 100 mg/kg of ISIS 537450, weekly for 4 weeks. Three groups of four C57BL/6 mice each were injected with 25 mg/kg, 50 mg/kg, or 100 mg/kg of ISIS 537452, weekly for 4 weeks. A group of 4 mice each were injected with 50 mg/kg of control oligonucleotide, ISIS 141923 (SEQ ID NO: 14), weekly for 4 weeks. A control group of mice was injected with phosphate buffered saline (PBS) administered weekly for 4 weeks. Mice were sacrificed two days after the final dose.

RNA Analysis

RNA was extracted from liver tissue for real-time PCR analysis of TMPRSS6, using primer probe set RTS3481. RT-PCR analysis of hepcidin was also conducted, using primer probe set RTS1777. The mRNA levels were normalized using RIBOGREEN®. As shown in Table 9, the antisense oligonucleotides achieved dose-dependent reduction of murine TMPRSS6 over the PBS control. Results are presented as percent inhibition of TMPRSS6, relative to control. As shown in Table 10, the antisense oligonucleotides achieved dose-dependent increase of murine hepcidin levels compared to the PBS control. Results are presented as percent increase in hepcidin, relative to control.

TABLE 9 Percent inhibition of murine TMPRSS6 mRNA levels in C57BL/6 mice Dose % (mg/kg/wk) inhibition ISIS 537450 25 45 50 76 100 90 ISIS 537452 25 56 50 88 100 100 ISIS 141923 100 27

TABLE 10 Percent increase in murine hepcidin mRNA levels in C57BL/6 mice Dose % (mg/kg/wk) increase ISIS 537450 25 28 50 110 100 372 ISIS 537452 25 55 50 268 100 349 ISIS 141923 100 109 Effect on Iron Levels

Unsaturated iron-binding capacity (UIBC) is frequently used along with a serum iron test to evaluate iron overload in hemochromatosis patients (Yamanishi, H. et al., Clin. Chem. 49: 175-178, 2003). These two tests are used to calculate the transferrin saturation, a more useful indicator of iron status than just iron or UIBC alone (Adams, P. C. et al., N Engl. J. Med. 352: 1769-1778, 2005). Iron levels and unsaturated iron binding capacity of the transferrin molecules were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Siek, G. et al., Clin. Chem. 48: 161-166, 2002). The results for iron levels, transferrin levels and percentage saturation of transferrin are presented in Tables 11 and 12, and indicate that treatment with ISIS oligonucleotides reduced iron levels and percent saturation of transferrin and increased transferrin levels.

TABLE 11 Iron levels of C57BL/6 mice Dose Iron (mg/kg/wk) (μg/dL) PBS — 109 ISIS 537450 25 102 50 56 100 38 ISIS 537452 25 93 50 53 100 44 ISIS 141923 100 87

TABLE 12 Percent saturation of transferrin and transferrin levels in C57BL/6 mice Dose Transferrin Transferrin (mg/kg/wk) saturation (%) (ng/mL) PBS — 35 122 ISIS 537450 25 28 136 50 14 151 100 9 159 ISIS 537452 25 25 142 50 11 164 100 8 183 ISIS 141923 100 23 144 Liver Function

To evaluate the effect of ISIS oligonucleotides on hepatic function, plasma concentrations of transaminases were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Nyblom, H. et al., Alcohol & Alcoholism 39: 336-339, 2004; Tietz N W (Ed): Clinical Guide to Laboratory Tests, 3rd ed. W. B. Saunders, Philadelphia, Pa., 1995). Plasma concentrations of ALT (alanine transaminase) and AST (aspartate transaminase) were measured and the results are presented in Table 13 expressed in IU/L. The ISIS oligonucleotides targeting TMPRSS6 were considered tolerable in the mice, as demonstrated by their liver transaminase profile.

TABLE 13 ALT and AST levels (IU/L) of C57BL/6 mice Dose (mg/kg/wk) ALT AST PBS — 45 79 ISIS 537450 25 50 95 50 22 62 100 24 66 ISIS 537452 25 17 38 50 54 60 100 38 76 ISIS 141923 100 112 172 Kidney Function

To evaluate the effect of ISIS oligonucleotides on renal function, plasma concentrations of BUN were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Nyblom, H. et al., Alcohol & Alcoholism 39: 336-339, 2004; Tietz N W (Ed): Clinical Guide to Laboratory Tests, 3rd ed. W. B. Saunders, Philadelphia, Pa., 1995). The results are presented in Table 14 expressed in mg/dL. The ISIS oligonucleotides targeting were considered tolerable in the mice, as demonstrated by their plasma BUN profile.

TABLE 14 BUN levels (mg/dL) of C57BL/6 mice Dose (mg/kg/wk) BUN PBS — 36 ISIS 537450 25 32 50 33 100 32 ISIS 537452 25 32 50 32 100 35 ISIS 141923 100 32

Example 3: Effect of Antisense Inhibition of Murine TMPRSS6 in HFE Knockout Mice

The effect of treatment of antisense oligonucleotide targeting murine TMPRSS6 was assessed in HFE^(−/−) mice. HFE^(−/−) mice have profound differences in parameters of iron homeostasis compared to wild-type littermates. Fasting transferrin saturation is significantly elevated and hepatic iron concentrations are significantly higher than control mice. The HFE knockout mice are therefore regarded as a standard model of hereditary hemochromatosis (Zhou, X. Y. et al., Proc. Natl. Acad. Sci. 1998. 95: 2492-2497).

ISIS 537450 (TTTCTTTCCTACAGAGACCC; SEQ ID NO: 9) is a 5-10-5 MOE gapmer, 20 nucleosides in length, wherein the central gap segment is comprised of ten 2′-deoxynucleosides and is flanked on both sides (in the 5′ and 3′ directions) by wings comprising five nucleosides each. Each nucleoside in the 5′ wing segment and each nucleoside in the 3′ wing segment has a 2′-MOE modification. The internucleoside linkages throughout the gapmer are phosphorothioate (P═S) linkages. All cytosine residues throughout the gapmer are 5-methylcytosines. ISIS 537450 targets murine TMPRSS6 mRNA (GENBANK Accession No. NM_027902.2, incorporated herein as SEQ ID NO: 1) with a target start site of 2933.

The effect of treatment of the mice with ISIS 537450 on TMPRSS6 mRNA and iron levels was assessed.

Treatment

A group of 12 male and female HFE^(−/−) mice were injected with 100 mg/kg of ISIS 537450 weekly for 6 weeks. A control group of 11 male and female HFE^(−/−) mice was injected with PBS weekly for 6 weeks. The mice were provided with normal chow during the study period. The mice were euthanized 2 days after the final dose of antisense oligonucleotide or PBS.

RNA Analysis

RNA was extracted from liver tissue for real-time PCR analysis of TMPRSS6, using primer probe set RTS3481 (forward sequence ATTCCACGCTGGGCTGTTAT, designated herein as SEQ ID NO: 15; reverse sequence CTGGTCAGGCCCCTTCAA, designated herein as SEQ ID NO: 16; probe sequence TGAACCCAGGCCAGGTCCTCCC, designated herein as SEQ ID NO: 17). RT-PCR analysis of hepcidin was also conducted, using primer probe set RTS1777 (forward sequence TGCAGAAGAGAAGGAAGAGAGACA, designated herein as SEQ ID NO: 18; reverse sequence CACACTGGGAATTGTTACAGCATT, designated herein as SEQ ID NO: 19; probe sequence CAACTTCCCCATCTGCATCTTCTGCTGT, designated herein as SEQ ID NO: 20). The mRNA levels were normalized using RIBOGREEN®. Treatment with ISIS 537450 achieved 88% reduction of murine TMPRSS6 over the PBS control. Treatment with ISIS 537450 also achieved 152% increase of murine hepcidin levels compared to the PBS control.

Effect on Iron Levels

Iron levels were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Siek, G. et al., Clin. Chem. 48: 161-166, 2002). The results for transferrin levels, iron levels and percentage saturation of transferrin are presented in Table 15, and indicate that treatment with ISIS oligonucleotides increased transferrin levels and reduced iron levels and percent saturation of transferrin. In comparison, iron levels in untreated wildtype mice (C57BL/6) shown supra are usually about 110 μg/dL, transferrin levels are about 122 ng/mL and the transferrin saturation is about 35%. Hence, antisense inhibition of TMPRSS6 in this model resulted in improvement of iron levels, transferrin levels and transferrin saturation levels close to that found in wildtype mice.

The iron levels in the liver and spleen were measured by Exova (Santa Fe Springs, Calif.). The data is presented in Table 16. The results indicate that antisense inhibition of TMPRSS6 resulted in a decrease in hepatic iron accumulation and increase in iron retention in the macrophages of the HFE^(−/−) mice. The reduction of iron from the liver tissue and the simultaneous absorption of unbound serum iron by macrophages indicate that antisense inhibition of TMPRSS6 in this model results in the amelioration of iron overload in tissues (Nemeth, E. et al., Science. 2004. 306: 2090-3).

TABLE 15 Serum iron levels, transferrin saturation and transferrin levels in HFE^(−/−) mice Serum iron Transferrin Transferrin (μg/dL) saturation (%) (ng/mL) PBS 318 93 132 ISIS 537450 142 26 183

TABLE 16 Iron levels in liver and macrophages of HFE^(−/−) mice (μg/g tissue) Liver Macrophages PBS 388 468 ISIS 537450 256 683

Example 4: Effect of Antisense Inhibition of Murine TMPRSS6 in th3/+ Mice

The th3/+ mice model, a model of β-thalassemia, harbors a heterozygous deletion of β^(minor) and β^(major) genes (Yang, B. et al., Proc. Natl. Acad. Sci. U.S.A. 1995. 92: 11608-12; Ciavetta, D. J. et al., Proc. Natl. Acad. Sci. U.S.A. 1995. 92: 9259-63) and exhibits features comparable to those of patients affected by β-thalassemia intermedia (TI). The effect of treatment with an antisense oligonucleotide targeting murine TMPRSS6 was assessed in th3/+ mice.

ISIS 537452 (GCTTAGAGTACAGCCCACTT; SEQ ID NO: 11) is a 5-10-5 MOE gapmer, 20 nucleosides in length, wherein the central gap segment is comprised of ten 2′-deoxynucleosides and is flanked on both sides (in the 5′ and 3′ directions) by wings comprising five nucleosides each. Each nucleoside in the 5′ wing segment and each nucleoside in the 3′ wing segment has a 2′-MOE modification. The internucleoside linkages throughout the gapmer are phosphorothioate (P═S) linkages. All cytosine residues throughout the gapmer are 5-methylcytosines. ISIS 537452 targets murine TMPRSS6 mRNA (GENBANK Accession No. NM_027902.2, incorporated herein as SEQ ID NO: 1) with a target start site of 3044.

The effect of treatment of the mice with ISIS 537452 on various parameters in the mice was assessed.

Treatment

A group of equal number of male and female th3/+ mice, 10-15-week old, was injected with 100 mg/kg of ISIS 537452 weekly for 6 weeks. A control group of male and female th3/+ mice was injected with PBS weekly for 6 weeks. The mice were provided with normal chow during the study period. The mice were euthanized 2 days after the final dose of antisense oligonucleotide or PBS. The male and female groups were separately assessed.

RNA Analysis

RNA was extracted from liver tissue for real-time PCR analysis of TMPRSS6, using primer probe set RTS3481. RT-PCR analysis of hepcidin was also conducted, using primer probe set RTS1777. The mRNA levels were normalized using RIBOGREEN®. The data is presented in Table 17. The results indicate that ISIS 537452 significantly reduced liver TMPRSS6 levels. Antisense inhibition of TMPRSS6 levels was associated with a modest increase in absolute hepcidin expression in the th3/+ mice. However, when the expression of hepcidin was normalized by the liver iron concentration, the difference between the th3/+ untreated and treated ice mice was significant, corresponding to a 3.4 fold increase in males and a 2.0 fold increase in females. TMPRSS6 and hepcidin levels are expressed as a percentage of the male PBS control group.

TABLE 17 % change in th3/+ mice TMPRSS6 Hepcidin PBS-Female +4 +34 ISIS 537452-Female −85 +64 ISIS 537452-Male −85 +67 Serum Analysis

Iron and transferrin levels were measured using an automated clinical chemistry analyzer (Hitachi Olympus AU400e, Melville, N.Y.) (Siek, G. et al., Clin. Chem. 2002. 48: 161-166). Transferrin saturation was calculated. The data are presented in Table 18, and indicate that treatment with ISIS oligonucleotides reduced iron levels and percent saturation of transferrin.

Total Bilirubin levels were also measured by the same clinical chemistry analyzer. The data is also presented in Table 18. The results indicate that antisense inhibition of TMPRSS6 resulted in a decrease in total Bilirubin levels of the mice. Further, the majority of bilirubin was indirect bilirubin (data not shown) in the th3/+ mice, indicating that antisense inhibition decreased hemolysis.

TABLE 18 Serum parameters in th3/+ mice Total Iron levels Transferrin Transferrin Bilirubin (μg/dL) (ng/mL) saturation (%) (mg/dL) Male PBS 199 138 63 0.32 ISIS 134 172 26 0.16 537452 Female PBS 179 135 55 0.30 ISIS 111 164 20 0.15 537452 Organ Analysis

Iron levels in the spleen and liver were measured by Diagnostic Center for Population and Animal Health (DCPAH) (Michigan State University, Lansing, Mich.). The data is presented in Tables 19 and 20. The results indicate that treatment with ISIS oligonucleotides reduced iron concentration in the liver. Measurement of the spleen weight indicated that antisense inhibition of TMPRSS6 also reduced spleen weight compared to the control groups. The spleen weight is expressed as a percentage to the weight measured in a group of mice at the start of the experiment. Pearl's Prussian Blue staining indicated that the iron in the spleen was predominantly localized in macrophages (data not shown) as expected by increased hepcidin expression. The reduction of iron from the liver tissue and the simultaneous absorption of unbound serum iron by macrophages indicate that antisense inhibition of TMPRSS6 in this model results in the amelioration of iron overload in tissues (Nemeth, E. et al., Science. 2004. 306: 2090-3).

Hence, antisense inhibition of TMPRSS6 reduces hepatic iron accumulation and splenomegaly associated with this mouse model (Pippard, M. J. et al., Lancet. 1979. 2: 819-21; Yang, B. et al., Proc. Natl. Acad. Sci. U.S.A. 1995. 92: 11608-12).

TABLE 19 Analysis of liver iron concentration in th3/+ mice Liver iron conc. (μg/dL) Male PBS 605 ISIS 537452 315 Female PBS 1321 ISIS 537452 816

TABLE 20 Analysis of spleen weight in th3/+ mice Relative spleen weight (%) Male PBS 1.1 ISIS 537452 0.1 Female PBS 1.6 ISIS 537452 0.1 Hematologic Analysis

Red blood cell (RBC) count, reticulocyte count, hemoglobin (HGB), and hematocrit (HCT) were measured at day 42 using an ADVIA120 hematology analyzer (Bayer, USA). The data are presented in Table 21, and indicate that treatment with ISIS oligonucleotides increased RBC count, HGB and HCT levels, and decreased reticulocyte count (i.e., the number of reticulocytes as a percentage of the number of red blood cells). The increased RBC and decreased reticulocyte count indicates that antisense treatment improved RBC production.

Furthermore, treated th3/+ mice exhibited lower MCH and MCV values suggesting, as previously observed (Gardenghi et al., J Clin Invest, 2010, 120:4466-4477), that lower transferrin saturation levels were associated with decreased iron intake and hemichrome formation.

The results indicate that antisense inhibition of TMPRSS6 improved the anemic phenotype in this model.

TABLE 21 Analysis of the anemic phenotype in th3/+ mice RBC Reticulocytes HGB HCT (×10⁶ cells/μL) (×10⁵ cells/μL) (g/dL) (g/dL) Male Day 0 8.3 1404 7.6 28.6 Day 42 11.1 472 9.2 34.5 Female Day 0 8.5 1818 7.8 30.5 Day 42 11.3 1029 10.0 36.5 

What is claimed is:
 1. A method comprising administering an antisense compound and a second agent to a subject, wherein the nucleobase sequence of the antisense compound is at least 90% complementary to a TMPRSS6 nucleic acid, wherein the antisense compound comprises a single-stranded, modified oligonucleotide, and wherein the second agent is an iron chelator.
 2. The method of claim 1, wherein the iron chelator is FerroKin, Exjade, Desferal, or Deferiprone.
 3. The method of claim 1, wherein the iron chelator is FerroKin.
 4. The method of claim 1, wherein the iron chelator is Exjade.
 5. The method of claim 1, wherein the iron chelator is Desferal.
 6. The method of claim 1, wherein the iron chelator is Deferiprone.
 7. The method of claim 1, wherein the subject has a disease, disorder and/or condition associated with excess accumulation of iron in the subject.
 8. The method of claim 1, wherein the iron chelator is administered at the same time as the antisense compound.
 9. The method of claim 1, wherein the iron chelator is administered prior to and/or following administration of the antisense compound.
 10. The method of claim 7, wherein the disease, disorder, and/or condition is polycythemia.
 11. The method of claim 7, wherein the disease, disorder and/or condition is hemochromatosis.
 12. The method of claim 7, wherein the disease, disorder and/or condition is anemia.
 13. The method of claim 12, wherein the anemia is hereditary anemia, myelodysplastic syndrome or severe chronic hemolysis.
 14. The method of claim 13, wherein the hereditary anemia is sickle cell anemia, thalassemia, Fanconi anemia, Diamond Blackfan anemia, Shwachman Diamond syndrome, red cell membrane disorders, glucose-6-phosphate dehydrogenase deficiency, or hereditary hemorrhagic telangiectasia.
 15. The method of claim 14, wherein the thalassemia is β-thalassemia.
 16. The method of claim 7, wherein the disease, disorder and/or condition is iron overload due to transfusion, excess parenteral iron supplement or dietary iron intake.
 17. The method of claim 1, wherein the modified oligonucleotide consists of 12 to 30 linked nucleosides.
 18. The method of claim 17, wherein the modified oligonucleotide comprises: a gap segment consisting of linked 2′-deoxy nucleosides; a 5′ wing segment consisting of linked nucleosides; a 3′ wing segment consisting of linked nucleosides; wherein the gap segment is positioned between the 5′ wing segment and the 3′ wing segment, wherein each nucleoside of each wing segment comprises a modified sugar, and wherein at least one internucleoside linkage of the modified oligonucleotide is a phosphorothioate internucleoside linkage.
 19. The method of claim 1, wherein the subject is a human subject.
 20. The method of claim 1, wherein accumulation of iron is reduced in the subject following administration of the antisense compound and second agent. 